Carlos A. Chavez Barajas

22nd, May 2013

Latest work :

• Data Analysis• Non-collision background estimation (SUSY searches) • W+Jets cross section (data driven Top bkg estimation)

• Trigger• Operations (on-call activities, and online work)• Software (developments and management)

2Data Analysis

• Estimation of non-collision background– SUSY searches:

• Hadronic inclusive (0-lepton analysis) • Monojet analysis

position of the muon segments in the CSC and the inner MDT endcaps (unpaired bunches)

JHEP 1304 (2013) 075

PLB 710 (2012) 67

Monojet AnalysisLowest threshold signal region

Algorithms combines muon timing information with calorimeter energy clusters position.Efficiencies typically 20-50 %

3Data Analysis

• W+Jets Cross section measurement (2011 data)– Test of pQCD– Background to Higgs and new physics– Extreme phase space test of MC predictions

• Many jets (6,7,8) in final state

• Data driven Top background estimation

Select a ‘pure’ ttbar sample by requiring events with one or two b-jets

studied Top mass and MET variables

Transverse Sphericity as independent variablefor template normalization

PRD 85 (2012) 092002

4Trigger Work

• Trigger Online Operations (On-call duties)– Trigger Online expert & Trigger Menu expert

• Monitoring and diagnosing of problems during data-taking • Need to take immediate actions with problems found online • Need to have extensive knowledge of Trigger menus and

configuration as well as the tools that handle these:– Preparation of trigger configuration for online running

– TriggerMenuPython – Prescale sets for different lumi scenarios

– TriggerRuleBook– Handle interface to Trigger Database for configuration and prescales

– TriggerTool

5ATLAS High Level Trigger

Dataflow

CTP decision & RoI address

RoI BuilderRoI Builder

L2 Supervisor (L2SV)

L2 Supervisor (L2SV)

L2 Processing Units (L2PUs)L2 Processing Units (L2PUs)

RODROD RODROD RODROD

ROBROBROBROB ROBROB

ReadOut System (ROS)

MuMu CaloCalo SiSi Detector Front-End

RoI R

eque

st

RoI D

ata

Data Flow Manager (DFM)

Data Flow Manager (DFM)

L2 Result

EF Processing Units (EFPUs)EF Processing Units (EFPUs)

Sub-Farm Input (SFI)Sub-Farm Input (SFI)

Sub-Farm Output (SFO)Sub-Farm Output (SFO)

HLT

6

Dataflow

CTP decision & RoI address

RoI Builder

L2 Supervisor (L2SV)

L2 Processing Units (L2PUs)

ROD ROD ROD

ROB ROB ROB

ReadOut System (ROS)

Mu Calo Si Detector Front-End

RoI R

eque

st

RoI D

ata

Data Flow Manager (DFM)

L2 Result

EF Processing Units (EFPUs)

Sub-Farm Input (SFI)

Sub-Farm Output (SFO)

HLT

X

XXX X

X X

X

ATLAS High Level Trigger

7Trigger Work

• Trigger Online Operations (On-call duties)– High Level Trigger release coordinator

• Responsible for online software deployments and testing• Needs to make sure that online software releases are free of bugs

• Required to have extensive knowledge of ATLAS software management systems

– NICOS System (nightly builds) http://atlas-computing.web.cern.ch/atlas-computing/links/distDirectory/nightlies/global/

– Trigger Release software installations Offline and Online at Point 1 – TagCollector system (handles all different software projects)

8Trigger Work

• Trigger Integration group – Responsible for maintaining software testing infrastructure for online

releases• ATN (Atlas Nightly Tests) and RTT (Run Time Tester) tests

– For High Level Trigger releases – http://atlas-computing.web.cern.ch/atlas-computing/links/distDirectory/nightlies/glob

al/

• Trigger Core Software group– Trigger configuration tool TriggerTool

• Interface to Trigger database• Needs optimization, already to slow when uploading new Menus and

configurations to DB• started working on implementing/redesigning

– To include future changes during LS1, L2-EF merging, new BunchGroup sets

• Online shifter training responsibilities– I trained Trigger shifters for control room activities from 2010

9Overview of Research

• I have demonstrated crucial involvement in Trigger operations• Quickly became part of approximately 5 online trigger experts• I played a central role managing and developing trigger software

• I have valuable experience with hardware and software• Developing and leading trigger software projects • Building and testing T2K calorimeters on time for installation• Collaborating well with group of people and ability to co-ordinate

– Data Quality Coordinator in BABAR

• Wide physics data analysis experience• SUSY searches and SM measurements in ATLAS• B and Charm physics from BABAR experiment

• ATLAS has a very exciting LS1 upgrade program and beyond• I am very keen on playing a central role in this program• I feel I can contribute effectively and make it a success

Carlos A. Chavez Barajas (CERN) 10

THANKS

Carlos A. Chavez Barajas (CERN)

11Sphericity

Carlos A. Chavez Barajas (CERN) 12

BABAR Experiment

• Branching Ratio measurement of B0->π0π0 =(2.1±0.6±0.3)x10-6

• Time integrated CP asymmetry Cπ0π0=(B0-B0)/(B0+B0) =-1.12±0.56±0.06

• Charmless two-body group – I provided and validated reduced datasets for several BF and CP-

asymmetry measurements– BR and Direct CP-asymmetry in B0->Kπ

• Constraining CKM angle α with BR and CP-asymmetries in B->ππ using Isospin relations

B -> ππ

Carlos A. Chavez Barajas (CERN) 13

D0-D0 mixing (BaBar)• Mixing is characterized by the parameters : x (ΔM) , y (ΔΓ) • By measuring the lifetime ratio CP even and CP-odd final states

and assuming CP-conservation the mixing parameter y = yCP:• D* tagged sample and untagged sample

2006 Babar Data Quality Coordinator (for one year)

Carlos A. Chavez Barajas (CERN) 15

T2K Ecal construction

• 4 Electromagnetic Barrel modules – Plastic scintillator and lead, optic fibers , MPPCs– Module dimensions approximately 2m X 4m

• During construction we carried out automatic radioactive source scans to measure light attenuation in the optic fibers, and validated the integrity of the detector

• Collaborating with several UK universities (including Warwick)• Several undergraduate, masters and PhD students involved in

the construction.

Carlos A. Chavez Barajas (CERN) 16

Carlos A. Chavez Barajas (CERN) 17

Carlos A. Chavez Barajas (CERN) 18

Carlos A. Chavez Barajas (CERN) 19