2011 Masterclass Debriefing: ATLAS W-path measurement

Content

1. Students’ Results

2. Website statistics

3. Brief analysis of feedback

4. Ideas for development

Interesting points

What makes a Masterclass “successful”?

How can we improve this

measurement?

The better preparation the better the

Masterclass ...

Videoconference !!!

1. Students’ Results 1 – brief refreshing

2

Structure of the proton

Student action? Identify elementary particles (electron (e-),

positron (e+), muon (μ-), antimuon (μ+) neutrinos)

Classify events

What to measure? Number of possible W events with e-, e+, μ+, μ-

What to calculate?

Why? Explore/Proof the inner structure of the proton

only ninteractio gluon-quark from sW' charged negatively of numberonly ninteractio gluon-quark from sW' charged positively of number

:R

sW' charged negatively of numbersW' charged positively of number

:WW

Search for the Higgs

Student action? Search for candidates with two W’s

What to measure? Number of WW events

Why? Search for interesting new physics

1. Students‘ Results 2

3

0 5 10 15 20 25 30 35 40 45 500.7

0.9

1.1

1.3

1.5

1.7

1.9

2.1

2.3Distribution of raw ratio values in the 2011 W-Path Masterclasses

Venue (coded by a number)

raw

rat

io:

W+

/W-

________raw ratio from ATLAS derived by the numbers of W’s in “Measurement of the W lnu and Z/gamma*ll production cross sections in proton-proton collisions at sqrt(s)=7TeV with the ATLAS detector”

________Weighted Average

1. Students‘ Results 3

4

1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 2.10 2.20

Measurement result of R± from the W-Path measurement of the International Hands on Particle Physics Masterclasses

(approx. 2000 students)

ATLAS Combined results

1. Students‘ Results 4

5

10 30 37 87

108

112

113

117

131

140

147

148

202

222

239

252

258

271

284

285

314

331

338

342

363

375

376

380

381

515

520

556

614

626

666

679

781

786

805

873

986

0

2

4

6

8

10

12

14

16

Frequency of events selected as Higgs candidate events(ATLAS W-path Masterclasses: approx. 2000 students)

Masterclasses event number

freq

uenc

y

2. Website statistics 1

6

Unique Visitors: 3,594

Number of Visits: 6,015

Number of visited pages: 44,573

(per visit) (7.4)

Bandwidth: 113.1 GB

Tutors preparation

Students came back to or

new guests reached the

website

Besides using DVD’s

institutes worked with

website as well

Why that many?

Data valid for the website www.cern.ch/kjende/*.htm and the period between March 01 and March 31 2011

2. Website statistics 2

7

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 240

10000

20000

30000

40000

50000

60000

70000

80000

Daily use of the ATLAS-MC-website in March 2011

Pages Hits Bandwidth in MB

2. Website statistics 3

8

0s-30s 30s-2mn 2mn-5mn 5mn-15mn 15mn-30mn 30mn-1h 1h+0

1000

2000

3000

4000 3018

595 407 562 443 532 458

Duration of website's visit

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 310

50

100

150

200

250Unique visits' Development of ATLAS-MC-website

unique visits

2. Website statistics 4

9

Browsers Top 5

Downloads Top 3

Connected to site from

Firefox 54%

Internet Explorer: 26%

Google Chrome: 8%

Apple Safari: 8%

Opera: 3%

Direct address: 54%

Links from external page: 29%

Links from Search Engine: 17%

Google: 95%

1. HYPATIA: 626

2. MINERVA: 623

3. Exercise2: 423

3. Brief analysis of feedback

10

F1: technical problems (MINERVA crashed) exercise introduction is very long with difficult definitions time problems

F2: • Instructions badly organized on separate pages; • idea of the measurement is very attractive• it’s nearly impossible in the given time to work out the Higgs finding• students can distinguish between signal and background but they cannot interpret

the W+/W- ratio• problem: getting students in pairs to download different event samples; size

restrictions; save procedure; • it’s great to have real LHC data

F3: event display program is not executable from DVD (problems in unzipping procedure)

F4: tutors needed a few hours to get into the matter; it was exciting

4. Ideas for development

11

1. Optimize the procedure: executable MINERVA on the DVD + organizing data samples in a specific event folder (DVD)

2. I will think about shorter instructions.

3. We will offer better step by step interpretations of both ratios.

4. We will prepare better documentation for tutors.

5. Prepare different data samples for each venue in order to more benefit from combining results (thus we will really see the statistic uncertainty shrinking)

6. Replace simulated Higgs events with real WW events

7. Offer possibility to students that work on the path at home to discuss and interpret their results (by creating an interactive platform)

8. I will do a didactic survey on the Masterclasses in 2012: we need to know when we call Masterclasses “successful” (students succeed in measurement, students have good feelings after attending Masterclasses, they achieved their learning objectives, ... )

4. Ideas for development

12

Room for your feedback – thank you!