1 / 12

Search for heavy Higgs in decays H  ZZ  ll nn and current status of the KIPT CMS Linux Cluster

Search for heavy Higgs in decays H  ZZ  ll nn and current status of the KIPT CMS Linux Cluster. L. Levchuk , D.Soroka, P.Sorokin, M. Voronko, and S. Zub Kharkov Institute of Physics & Technology, 61108 Kharkov, Ukraine. Physics motivation. So far, no evidence for light

elkan
Télécharger la présentation

Search for heavy Higgs in decays H  ZZ  ll nn and current status of the KIPT CMS Linux Cluster

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. Search for heavy Higgs in decays HZZllnn and current status of the KIPT CMS Linux Cluster L. Levchuk, D.Soroka, P.Sorokin, M. Voronko, and S. Zub Kharkov Institute of Physics & Technology, 61108 Kharkov, Ukraine

  2. Physics motivation • So far, no evidence for light (M120 GeV/c2) SM Higgs • HZZllnn has ~6 times greater BR compared to HZZ4l • Search for resonances in ZZ system

  3. Previous studies • N.Stepanov, CMS-TN/93-087 (1993); I.Gaines, D.Green, S.Kunori, J.Marrafino, J.Womersley, and W.Wu, CMS-TN/95-84 (1995); … heavy (MH>500 GeV/c2) Higgs observability via HZZll was studied • L.Levchuk et al., 6th, 7th and 8th Annual RDMS/CMS collaboration meetings (2001-2003) MH=200250 GeV/c2; ways to eliminate IB by tuning cuts to qqHq & ggHg Goals of this study • Optimization (tuning to WBF qqHqq, etc.) of event selection criteria for MH~200 GeV/c2 • Extension toMH=250450 GeV/c2

  4. Simulation tools Background contributions • PYTHIA (Ver. 6.205) • CMSJET (Ver. 4.703) • Z+jets • ZZ • ZW “Irreducible” background _ 75 Mevts forZ+jets and 10 Mevts fort t have been generated

  5. Suppression of background to H0Z0Z0ee() +  events _ (MH = 200 GeV/c2) ETmiss > 30 GeV; 2 leptons such that : |l|<2.4, pTl >20 GeV/c, pTll>30 GeV/c, |MZ-Mll| < 5 GeV/c2; pTllpTmiss 90(jets); nob-jets (pTjet>20 GeV/c); Njets 1 or 2 for pTjet>20 GeV/c, 1.0  |jet|  4.5 “1st level” cuts For Njets 1: ETmiss 40  GeV; pTllpTjet 120; pTmisspTjet 120; pl1pl2 60; pTl1pTl2 90; For Njets 2: |jet1– jet2|  4.2; Mjj 600  GeV/c2; 2.0  |jet|  4.5; pTjet1pTjet2 90; jet1jet2 0; cos(pl1pl2)  0.4 “2nd level” cuts

  6. _ H0Z0Z0ee() +  vs. background

  7. “Combined” event selection criteria

  8. Suppression of background to H0Z0Z0ee() +  events (MH = 400 GeV/c2) “1-st level” cuts: ETmiss > 60 GeV; 2 leptons such that : |l| < 2.4, pTl >20 GeV/c, pTll > 40 GeV/c, |MZ-Mll| < 6 GeV/c2; nob-jets for pTjet>30 GeV/c; no jets for pTjet>100 GeV/c “2-nd level” cuts: N jets > 0, 30 GeV/c < pTjet < 100 GeV/c

  9. _ H0Z0Z0ee() +  vs. background

  10. (current status)

  11. KIPT CMS Cluster (KCC) Performances: 11 nodes (22 CPU’s, 38 Gflops), 2.5 TB HDD LCG Middleware: ver. LCG-2_2_0 installed and configured Production in 2004: 150 Kevts (CMKINCMSIMHITS) generated and transferred to CERN KCC is a part of the MOSCOW Distributed RC KCC resources are allocated to CMS jobs exclusively

  12. Conclusions & plans • The results suggest that heavy (MH=200500 GeV/c2) Higgs can be observed with CMS in decays HZZllnn • this has been illustrated by fast MC simulation for MH close to HZZ decay threshold as well as for very heavy (MH=400 GeV/c2) Higgs • conclusions seem to be valid to the extent, at which one believes PYTHIA and CMSJET • use/development of an alternative generator, which would take into account 23 hard processes of non-resonant ZZ/ZW production is desirable • Simulations with FAMOS and (prob.) OSCAR are planned • Current status of the KIPT CMS Cluster (KCC) allows us to proceed with participation in CMS MC production • LCG-2 middleware has been installed and configured • Considerable increase of the KCC capacity is planned to provide KIPT participation in CMS data analysis • bandwidth of KIPT internet channel is still unsatisfactory; work is under way to improve the situation

More Related