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Introduction to Dijet Resonance Search at 13 TeV

Introduction to Dijet Resonance Search at 13 TeV. Robert M. Harris Fermilab On Behalf of the Dijet Team September 29, 2014. Outline. Motivation Publication History & 13 TeV Expectations Dijet HPA and Extensions People and Meetings Conclusions. q, q, g. q, q, g. X. q, q, g.

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Introduction to Dijet Resonance Search at 13 TeV

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  1. Introduction to Dijet Resonance Search at 13 TeV Robert M. Harris Fermilab On Behalf of the Dijet Team September 29, 2014

  2. Outline Motivation Publication History & 13 TeV Expectations Dijet HPA and Extensions People and Meetings Conclusions

  3. q, q, g q, q, g X q, q, g q, q, g Motivation • Search: Dijet Resonances • Powerful: LHC in run 2 is a dijet resonance factory at a new energy scale • Broad: search for many sources of new physics in a single simple search • String resonances from string theory • Excited quarks from theories of quark compositeness • W’, Z’ and scalar diquarksfrom grand unified theory • Gravitons from the Randall-Sundrum model of extra dimensions • Axigluons, Colorons and Color Octet Scalars from other new models • Model Independent: Publish cross section limits that can constrain any present or future model of narrow qq, qg, or gg resonances. Robert Harris, Fermilab

  4. Publication History of Search at CMS • This exciting analysis has been published frequently by CMS, often very early in the run, and the papers are highly cited • Early publications at new energies get more citations. • 3 pb-1 @ 7 TeV: Search for Dijet Resonances in 7 TeVpp Collisions at CMS, Phys.Rev.Lett.105 (2010) 211801, 126 citations. • 1 fb-1 @ 7 TeV: Search for Resonances in the Dijet Mass Spectrum from 7 TeVpp Collisions at CMS, Phys.Lett. B704 (2011) 123-142, 138 cites. • 5 fb-1 @ 7 TeV: Search for narrow resonances and quantum black holes in inclusive and b-tagged dijet mass spectra from pp collisions at sqrt(s) = 7 TeV, JHEP 01 (2013) 013, 36 citations • 4 fb-1 @ 8 TeV: Search for narrow resonances using the dijet mass spectrum in pp collisions at sqrt(s) = 8 TeV, Phys. Rev. D 87 (2013) 114015, 62 citations • 20 fb-1 @ 8 TeV: publication draft with ARC, public PAS EXO-12-059.

  5. Expectations @ 13 TeV 2015 Schedule from T. Camporesi on 6/23/14 A. Weiler 6/23/14 • With 1 fb-1 expected from the first 3 week run in May or June 2015 the mass limit on q* would be 4.6 TeV • With 100 pb-1, ~2 days data, we reach current CMS limit of 3.5 TeV ! • Approve analysis in summer 2015 !

  6. Example of analysis from draft paper • Search of spectrum and limits on narrow resonances • Background modeled with same parameterization in all five papers. • Signals modeled with q* (qg) and RSG samples (qq and gg).

  7. General Issues for Dijet HPA • Dijet resonance search is sensitive to new physics right away • Within days of running at 13 TeV we are exploring new territory ! • The analysis needs to be ready to run on first data samples • Weekly check of dijet mass plot, background fit, and (data – fit)/error • Need to be organized and keep the HPA analysis simple • Following as much as possible the understood 8 TeV analysis steps • See presentation by Francesco Santanastasio with assigned tasks • Challenge may be understanding jet object and trigger rapidly • Close coordination with JetMET in understanding JEC and jet object • See presentations to follow by Mikko Voutilainen and Niki Saoulidou • Understand the trigger efficiency turn-on for trigger (HT, PFHT, …) • See presentation by Maxime Gouzevitch Robert Harris, Fermilab

  8. Related Non-HPA Analyses • These benefit from understood and approved HPA dijet resonance search • Reuse the baseline analysis technique and adds a new feature for a little more sensitivity or a broader interpretation of the data. • Tagged Dijet Resonance Searches • b, W / Z, H and q/g jet tagging (see presentation by Sertac Ozturk) • Additional Categories of Limits • Wide dijet resonance shapes and Quantum black hole shapes • Spin sensitive searches • Simultaneous searches in dijet mass and angle (bins of Dh or cos q*) • Extending the search to lower mass resonances • Using data scouting datasets or pre-scaled triggers at lower dijet mass • All interesting, but none are needed for the first HPA result. • Recommend limiting the scope to keep the HPA simple and fast Robert Harris, Fermilab

  9. People So Far • People from 8 TeV search interested in 13 TeV search • John Paul Chou • Dinko Ferencek • Maxime Gouzevitch • Emine Gurpinar (student) • Robert Harris • Andreas Hinzmann • Bora Isildak • Shuichi Kunori • Sung-Won Lee • Sertac Ozturk • Maurizio Pierini • Francesco Santanastasio • New people interested in 13 TeV search • Ayse Bat (student) • Christopher Cowden • M. Diamantopoulo (student) • Giulia Dimperio (student) • Kostas Kousouris • Georgios Mavromanolakis • Juska Pekkanen (student) • E. Sagkrioti (student) • Nikki Saoulidou • Erini Tziaferi • Mikko Voutilainen • An experienced group with multiple students

  10. Meetings so far • June 26 • First organizing meeting during CMS Week • September 12 • Discussed root tree maker and this mini-workshop • September 26 • Discussed assignment of tasks • We will continue to meet at least bi-weekly on Fridays from 16-17:00 Robert Harris, Fermilab

  11. Conclusions • We plan to search for narrow dijet resonances in run 2. • Analysis is mature, with five publications expected from run 1 • We have assembled a team and begun to assign tasks • An experienced team including multiple new Ph.D students • We could discover new physics with 1 fb-1 of run 2 data. • We are as sensitive as run 1 with about 100 pb-1 of run 2 data • We plan for an approved result for summer 2015 conferences Robert Harris, Fermilab

  12. Backup Robert Harris, Fermilab

  13. Dijet Resonance Ph.D Theses 1. KazimGumus (2008) - preparation CERN-THESIS-2008-066 https://cds.cern.ch/record/1121435 2. SertacOzturk (2011) - 7 TeV (~3/pb) CERN-THESIS-2011-007 https://cds.cern.ch/record/1340571 3. ChiyoungJeong (2011) - 7 TeV (~1/fb) CERN-THESIS-2011-267 https://cds.cern.ch/record/1462016 4. EmineGurpinar (2014?) - 8 TeV (~19/fb) TBC Robert Harris, Fermilab

  14. Additional Reading “Searches for Dijet Resonance at Hadron Colliders” R. Harris and K. Kousouris Int. J. Mod. Phys. A26 (2011) 5005-5055 arXiv:1110.5302 Robert Harris, Fermilab

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