Monitoring Muons Physics 2 top di-boson SUSY Dark

Monitoring Muons; Physics 2: top, di-boson, SUSY, Dark Matter Melissa Franklin DOE Review 2009

Muon Data Quality Monitoring: Harvard contributions • Moed, Kagan, Guimaraes, Belloni, Martinez, Prasad started the muon monitoring project at ATLAS from Harvard. • Moed and Kagan wrote the code in the DQMF framework to monitor all muon chambers(MDT, RPC, TGC) at Level 1 and Level 2 based on Gnam histograms, make decisions as to which chambers are not working properly etc. and write displays to show what is working or what is not. • Continually updated DQMF framework with new releases • And established an input/output connection to the database • Belloni, Martinez, Prasad, Guimaraes became muon detector, readout and offline monitoring experts. They also became the experts who taught others to run shifts. • Key participants in the muon run analysis task force 8/21/2009 M. Franklin - DOE Site Visit 2

New/old monitoring effort Most online monitoring of raw data using DQMF MUON • Continuously sampling data from the RODS (Level 1) • Gnam application also running on Calibration stream (Level 2) but we are not looking yet 8/21/2009 M. Franklin - DOE Site Visit 3

Monitoring tasks accomplished • Experts in Muon Online Data Quality Monitoring since 2007 -- Maintained at least 1 expert at CERN since project began (Shulamit Moed and/or Michael Kagan) -- Experts in all data quality tools available for MDT shifter-- Responsible for MDT DQMF online monitoring sw infrastructure-- We define and develop the DQMF structure for MDTs (~7000 histograms monitored)-- We develop additional automated tools and algorithms to study MDT online data with DQMF-- Use these tools to determining the quality of the data, and identify/study problems in real time -- Responsible for defining how MDT data should be monitored online, how the tools can best asses data quality, and how to interface the tools best with the MDT shifterﾊ -- Helped develop DQMF online monitoring infrastructure for RPC and TGC -- Currently help all Muon sub systems maintain and develop tools for DQMF online monitoring-- Responsible for training MDT shifters in Data Quality monitoring -- Hold the ﾒMuon data quality toolsﾓ session during Muon shifter training sessions Status and Developmentsﾊ -- Spent a great deal of time studying the data and understanding the problems, and tuning our monitoring structure, algorithms and error thresholds -- When we began, system was in chaotic state, difficult to understand data, and difficult to define tests to properly identify problems (many chambers would fail our DQMF tests)-- As of August 2009, Only 25 -35 out of ~1100 chamber fail our DQMF tests. We are investigating each of these problems, many of which we already understand -Developed graphical interface for MDT system online monitoring with DQMF. -- Greatly increases the ability of the shifter to navigate large MDT system, study data and identify problems -- Developed tools for automated archiving of data quality results into Databases -- Develop and maintain MDT online monitoring documentation / twiki-- Constantly in Control room monitoring MDTs during data taking, both while on and off shift Harvard will maintain its role as Muon Online data quality experts at CERN as we approach first beam of the LHC -- Michael Kagan will be present at CERN as expert-- Two 3 rd year students (Laura Jeanty and Giovanni Zevi della Porta) also at CERN, becoming Muon monitoring experts. Expanding our efforts to offline monitoring -- Not all problems identified online can be solved online-- Using our expertise in MDT online data and taking a larger role in understanding problems in offline data-- Following problems from online to offline and solving them with complete offline data sets-- Beginning to understand how to correlate MDT data problems with other ATLAS sub systems-- One example: spikes recently found in the TDC spectrum of MDT. 8/21/2009 M. Franklin - DOE Site Visit 4

Level 1 monitoring 8/21/2009 M. Franklin - DOE Site Visit 5

Gna. Mon: A Gnam Histogram Interpreter • MDT specific stand-alone tool (not in tdaq) – – – Can be used online and offline: Runs on Gnam root files Performs statistical analysis without need of reference histograms Highlights suspicious tube clusters like multilayers, tube layers, mezz. Dropped chambers Hit occupancy overview for the MDT’s from GNAMON Run: 125032 TGC triggering bottom half 8/21/2009 M. Franklin - DOE Site Visit 6

Test integration case: Spikes in ONLINE monitoring TDC spectra Chi-square fit fail --->> DQMF warning to shifters Improve fitting algorithm to identify spikes 8/21/2009 M. Franklin - DOE Site Visit 7

Move to offline to investigate Spike events have tens of thousands of MDT hits! Often the “charge” associated with hits in spikes is zero 8/21/2009 M. Franklin - DOE Site Visit 8

Is there a pattern in crates, grounds, ? 8/21/2009 M. Franklin - DOE Site Visit 9

Summary of monitoring plans • Laura Jeanty, Michael Kagan, Giovanni Zevi della Porta, Shulamit Moed(ex-officio), Melissa Franklin, new post-doc • New group taking advantage of the wide knowledge of Harvard muon group who will work on finding and fixing problems found by monitoring while improving monitoring • Use online, calibration stream, offline, knowledge of DAQ, DQMF, GNAM , pulser runs etc to solve problems • Post-doc resident at CERN arriving fall 8/21/2009 M. Franklin - DOE Site Visit 10

Physics 2 Overview What we thought in the spring!

Use top physics to look beyond the SM Guimaraes, Franklin, Morii, Mills, Belloni, Prasad(5), Smith(5) + Prasad thesis- top cross-section 50/pb Smith thesis - ttbar resonance New schedule --> Smith thesis WZ cross-section 50/pb

pp X ttbar + x • • Many models for new physics (extra dimensions, little Higgs, SUSY…. ) predict heavy resonances, some of which (notably the Randall-Sundrum gluon) couple preferentially to top Tevatron limits are model dependent but exclude resonances below ~1 Te. V Can significantly extend this reach at 14 (and even 10) Te. V As mass of resonance increases, decay products of top become increasingly collimated experimental challenges – – overlapping jets nonisolated leptons from W decay To the left: number of reconstructed jets cone algorithm, cone = 0. 4 3 jet bin many signal events, particularly for 2 Te. V resonance few events from ttbar (dominant background) but: W+jets may become important p. T > 20 Ge. V Identifying a jet from two partons (such as from the two quarks of a W decay) 8/21/2009 M. Franklin - DOE Site Visit 13

Identifying Merged Jets • Jet Eccentricity – – • • geometrical measure of elongation of jet energy deposit in the calorimeter 0 = circular, 1 = highly elliptical/elongated Uncorrelated with jet mass, another good discriminant ATL-com-phys-2009 -338 8/21/2009 M. Franklin - DOE Site Visit 14

WZ feasibility studies • W+Z l+l-l+ : motivation – “bread and butter” Standard Model measurement – Key background for same-sign lepton and trilepton searches – Develop understanding of multilepton data, technology for estimating backgrounds • Back-of-the-envelope feasibility check: cross section measurement with 100 pb-1 – 10 Te. V • S/B ~ 5 ~36/7 – 7 Te. V • S/B ~ 5~20/4 • Promising enough to take the next step • More detailed assessment of expected precision 8/21/2009 M. Franklin - DOE Site Visit 15

Cross-section [pb] Top with low energy and small sample 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Generated di-lepton top (e/m) signal samples at 4, 5, 6, 7, 8, 10 Te. V Selection eff. For dilepton events flat across energy range 3 5 7 9 CM energy [Te. V] events in 50/pb Selected E (Te. V)sel eesel em sel mm 4 4 11 5 5 8 22 10 6 13 36 16 7 20 53 25 8 27 81 35 10 50 134 62 8/21/2009 M. Franklin - DOE Site Visit 16

Top cross-section • Lepton+jets • Prasad thesis # of events with hi pt muon and jets in 50/pb Plot made before latest CERN announcement 8/21/2009 M. Franklin - DOE Site Visit 17

New physics with di-leptons in the longer term SUSY, Dark Matter etc • Laura Jeanty(3), Giovanni Zevi della Porta(3), Mills, Franklin … 8/21/2009 M. Franklin - DOE Site Visit 18

Same Sign Dilepton Signature for SUSY • Putting together possible gluino decays – jets (also possible with squark production) • One illustrative decay process: q g g g ~ q ~ g q ~ l ~ ~ q ~ g ~ q’ ~ o q’ l l W ~o leptons missing energy 8/21/2009 M. Franklin - DOE Site Visit 19

Same Sign Dilepton Signature: Motivation • How often does a gluino pair produce same sign dileptons? 100% ~60%: q = t • ~ ~ t ~ g t 97% b 22% l W ~o Other contributing decays from gluino decaying to sbottom gluino decays to isolated lepton: 26% gluino pair decays to dileptons: 7. 5% gluino pair decays to same sign dileptons: ~4% Total branching fraction to same sign leptons ~ 4% – 12% if include top or bottom leptonic decays – for comparison, 40% of gluino decays have no leptons • The signature has multiple handles - leptons, jets, missing energy • Does not rely on missing energy and jets alone, unlike other SUSY searches 8/21/2009 M. Franklin - DOE Site Visit 20

Can we trigger on it? Low pt leptons>hard to trigger 8/21/2009 M. Franklin - DOE Site Visit 21

SUSY backgrounds: our specialty 8/21/2009 M. Franklin - DOE Site Visit 22

8/21/2009 M. Franklin - DOE Site Visit 23

Discover dark matter at the LHC Recent results in astrophysics suggest a possible dark matter candidate which could be produced at the collider

Possible production mechanisms @ LHC 8/21/2009 M. Franklin - DOE Site Visit 26

Clear signature - lepton jets 8/21/2009 M. Franklin - DOE Site Visit 27

Analysis summary Study di-leptons WZ, ttbar, SUSY initially; ttbar resonance, dark matter, more SUSY over time Study Z cross-section, Z pt, Z + jets angular distributions initially: ZHiggs, Z’, Zgamma over time