International

Masterclasses 2013

Farid Ould-SaadaOn behalf of IMC steering group& authors of the material presented

International Masterclasses 2013

25.2 – 22.3

• 130 institutes, 163 Masterclasses

(2012: 117 / 143)• 37 video conferences (mostly 4-5

institutes)– 12 on ATLAS Z (57 institutes)– 12 on ATLAS W (55 institutes) – 10 on CMS (40 institutes)– 3 on ALICE (10 institutes)

• 25 moderators at CERN http://www.physicsmasterclasses.org/index.php?cat=schedule#moderators

– Moderators training on Feb 18

• + separate Masterclasses + Teacher Days

• +US Masterclasses (videos@Fermilab)– http://quarknet.us/library/index.php/

Schedules_2013– 7 on CMS (21 institutes)– 5 on ATLAS Z (13 institutes) 

IMC 2013Running in 37 Countries

New countries:

• Romania (Bukarest)

• Turkey (Ankara, METU)

• Cyprus (Nicosia)

• Palestine (Birzeit)

• Egypt (Alexandria)

Rejoiner:

• Südafrika (Durban, Cape Town)

New ATLAS Zpath• Master the invariant mass

technique – to study and measure the Z boson

and other resonances (J/) decaying to l+l-

– to search for new physics (Z’)– to search for the Higgs boson in

and l+l-l+l-

• HYPATIA event display

• Data from 2011– 13000 events ~2.5 GB (password protected, 100 free)

– 13 directories, 20 groups (A-T), and 50 events/mixed sample/2 students

– 50% Z, 30% 10% (J/, 5% Z', 5% l+l-l+l-

– Higgs candidate events:

– 1 fb-1 according to ATLAS publication

– 125 GeV Higgs MC signals ready to upload (1fb-1, 10fb-1,25fb-1 )

M()=125 GeV

M(ee)=123 GeV

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New ATLAS Zpath tests

• OPloT: – Mll and/or M and/or Mllll to be

discussed locally– Moderator: 1 slide with 3

invariant masses; Invariant mass as a tool to identify particles, to discover new particles, and to search for exotic particles

• Web pages updated and measurement ready

– http://www.physicsmasterclasses.org/exercises/ATLAS-2013/en/zpath.htm

– Introduced Higgs – Described new measurements– Prepared material for

instructors, moderators, for discussions, …

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OPloTTests 2013

• Higgs comments– 4l provided without

requiring 2l from Z, with lower cut on other pair

– provide MC with 125 Higgs and background

– Upload 125 Higgs MC ((1)&10 & 25 fb-1)

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or e+e-? • Left: pT>1GeV; right pT>5 GeV

– 2 apparent tracks pointing to 2 calorimeter objects

• Zoom reveals 2-pairs e+e- – Left pair disappears if at least 2

pixel hits are required (bottom)– Each pair has an invariant mass

of ~0.1 GeV, i.e. consistent with a photon conversion! (circle)

– We are in presence of 2-photons, both converted.

– The invariant mass of the 4 electrons is ~134 GeV [square]

• Calorimeter object information

• The conclusion is that the 2 calorimeter objects correspond to 2 photons, which have converted and lead to 4 tracks; the tracks from one pair had less than 3 pixel hits

• So, to be classified and entered as 7

• Measurements– Wl– W+/W- ratio– Angular distribution

between leptons in WW events

• MINERVA event display• Improvements

– 2011 real data: 693 WW/Higgs candidates mixed with 5307 W and other background events

– Histogram tool has been improved

– spreadsheet and histogram websites connected with database

• New measurement tested

New ATLAS W-path with real WW (+H) events

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New ATLAS W-path

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Measurements• J/ for schools, workshops• W/Z for IMCImprovements• Better transfer of results• Now in 11 languages• Add a small number of Higgs

candidates (4 leptons only).New• Masterclass on the road• Tested improvements in BeijingClose to ready for IMC 2013

CMS measurements

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Measurement• Option 1

– Strangeness: decay patterns of V0s: K0s, Λ, anti-Λ from p-p collisions

• Option 2– Measure nuclear suppression factor RAA

New and noteworthy• visual analysis:

– 30 events (2012) , 15 events (2013)• Samples

– Small p-p at 7 TeV – large pb-pb at 2.76 TeV

• p-Pb collisions in 2012 – show different result from Pb-Pb samples:

evidence of hot plasma?

ALICE measurements

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• D0K– 2010 minimum bias data

• Usual kinematic/geometric/PID/event variables available in ntuple

1. fitting mass distribution

2. obtaining signal variable distributions

3. reducing background contamination

4. measuring the D0 lifetime

• No event display

Targeted at undergrads or summer school students from other experiments,

Being adopted/simplified for a Masterclass

Some work needed before …

Possible pilot run with a few institutes in 2013

Aim at deployment for IMC 201

LHCb – lifetime of Do

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IMC coordination

• IMC Coordination– Dresden just signed a contract with the CERN DG, which assures the– Financing of Uta Bilow (Dresden) for the next years as IMC coordinator – Includes Europe / Middle East / Africa – America / Far East / Australia coordinated by Ken Cecire (Notre Dame) and

supported by Quarknet

• IMC steering group and the IPPOG co-chairs – working to establish a document: mandate of group, membership, quality

assurance, procedure for new measurements, …

• Currently measurements from ALICE, ATLAS, CMS– LHCb measurements expected in 2014; working on pilot tes with a few institute in

2013

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