1 / 15

Measurement of H → WW* fully hadronic in HZ at 350 GeV

Measurement of H → WW* fully hadronic in HZ at 350 GeV. Mila Pandurovi ć. Introduction. HZ @350GeV σ ( e + e - →HZ)=134 fb  68000 ZH evts H→WW→qqqq , Z →ff, f=e, μ ,q Motivation: precision of the measurement of Signal evts : BF( H→WW qqqq )~10 %

peri
Télécharger la présentation

Measurement of H → WW* fully hadronic in HZ at 350 GeV

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measurement of H→WW* fullyhadronic in HZ at 350 GeV Mila Pandurović

  2. Introduction HZ @350GeV σ(e+e- →HZ)=134 fb 68000 ZH evts H→WW→qqqq , Z →ff, f=e,μ,q Motivation: precision of the measurement of Signal evts: BF(H→WWqqqq)~10% 1. BF(Z→ll , l=e,µ)~7%  1%~ 500 evts 1/sqrt(N)~5% BF(Z→qq) ~70%  7% ~4800 evts 1/sqrt(N)~1.5 %

  3. Signal and background processes

  4. Analysis strategy Semileptonic FS: 4 jets + 2l Lepton isolation Nlept =2 FastJetFinder: Kt ex, Njets=4, R=1.2 Hadronic FS: 6 jets Lepton isolation Nlept=0 FastJetFinder: Kt ex, Njets=6, R=1.2 Preselection Multivariate analysis Extract NS, NB to get

  5. Lepton definition 4jets+2electrons Lepton definition: track energy of a lepton candidate > 12 GeV Z→ee Econe[GeV] signal Etrack[GeV] Selection: - Track energy of a lepton candidate > 12 GeV  85 % reconstructed with 2 muons Cone angle : Cos θ=0.995 counts signal electrons PFO 5 Etrack[GeV]

  6. Lepton definition 4jets+2 muons Econe[GeV] Z→µµ signal Etrack[GeV] counts Selection: - Track energy of a lepton candidate > 12 GeV  84 % reconstructed with 2 muons Cone angle : Cos θ=0.995 Muons electrons PFO 6 Etrack[GeV]

  7. Preselection & BDT application 4jets+2l Preselection : reducing ‘hadronic’ background: qqqq, qqνν Testing additonalpreselection cuts: Event shapes - signal 4 jets, the most persistant background qqll, qql 2 jets

  8. Variables4jets+2 electrons BDT trained on : HZ, Z-ll, non WW-qqqq decays qqll 3. qql Total signal Eff=30 %

  9. BDT application 4jets+2muons BDT trained on : HZ, Z-ll, non WW-qqqq decays qqll 3. qql Total signal Eff=33 %

  10. Lepton definition 6 jets Econe[GeV] signal Etrack[GeV] Simultaneous reconstruction of the real W, Z, Higgs. Reduced chi2 used. Producin the new one with resolutions.

  11. Preselection 6 jets Preselection optimized to reduce ‘semileptonic’ bck.

  12. Variables6jets BDT is trained on: 1. qqqq 2. HZ, (other H decays, Z→qq) Total signal Eff=50 %

  13. Summary Analysis is coming to an+ end! Redoing 6jets with the adaquite chi2 definition – hoping for the improvement in the masses reconstruction. Will include new backgrounds but expecting easy reduction with preselection cuts only. Systematics: is Jet resolution the most critical?

  14. END

  15. Variables ANGLES 6 jets FS

More Related