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Vi rtual C ol l i ders for C i ti zen Sci enti sts p p LHC Physics Center at CERN

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P e t e r S k a n d s C E R N T h e o r e t i c a l P h y s i c s U n i t

Vi rtual C ol l i ders for C i ti zen Sci enti sts

p p

LHC Physics Center at CERN
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SLIDE 2
  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

CERN: European Organization for Nuclear Research

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Every day, around 10 000 scientists from all over the world.

20 European Member States and around 60 other countries collaborate in our scientific projects.

Flags of CERN’s Member States

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

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the Tools of the trade

  • 2. Detectors : gigantic

instruments recording the particles spraying out from the collisions.

  • 1. Accelerators : powerful

machines to accelerate particles up to extremely high energies and bringing them into collision with other particles.

  • 3. Computers : collecting,

stocking, distributing and analyzing the enormous amounts of data produced by the detectors.

27 km 100 m

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SLIDE 4
  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

Nutshell

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Theory Experiment

Adjust this to agree with this

→ Science

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SLIDE 5

P e t e r S k a n d s : C E R N P i l o t P r o j e c t

In Practice

VINCIA PYTHIA …

“Virtual Colliders” = Simulation Codes

→ Simulated Particle Collisions

Real Universe → Experiments & Data

Particle Accelerators, Detectors, and Measurements → Published Measurements 5

“Events” “Histograms”

Relativity, Quantum Theory, Physics Models, Algorithms, …

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LHC Collision at 7 TeV ATLAS, March 2010

CERN - The Large Hadron Collider (LHC)

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T h e o r y ↔ D a t a

Global Comparisons

O v e r 7 0 0 b i l l i o n s i m u l a t e d c o l l i s i o n e v e n t s 7 0 0 0 V o l u n t e e r s - 2 0 0 0 0 H o s t s

  • J. Blomer,
  • P. Buncic,
  • I. Charalimpidis,
  • F. Grey,
  • A. Haratyunyan,
  • A. Karneyeu,
  • D. Lombrana-Gonzalez,
  • M. Marquina,

B.Segal,

  • P. Skands,

HERA SLC LEP RHIC

LHC

Tevatron

SPS ISR

Task: determine “best” parameters for theory models → Compare against thousands of measurements, taken under different conditions, by different experiments, at different colliders + do this for many simulators & versions, with different setups

LHC@home 2.0

TEST4THEORY

Quite technical Quite tedious → Ask someone else everyone

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SLIDE 8
  • P. Skands

Virtual Colliders

LHC@Home 2.0 - Test4Theory

Idea: ship volunteers a virtual atom smasher

(to help do high-energy theory simulations)

Runs when computer is idle. Sleeps when user is working.

Problem: Lots of different machines, architectures

Use Virtualization (CernVM) → provides standardized computing environment on any machine (in our case: Scientific Linux) → replica of our normal working environment. Factorization of IT and Science

Infrastructure; Sending Jobs and Retrieving output

Based on BOINC platform for volunteer clouds (but can also use other distributed computing resources, like GRID or traditional farms) New aspect: virtualization, never previously done for a volunteer cloud

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http://lhcathome2.cern.ch/test4theory/

(tedious, technical)

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

Test4Theory

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New Users/ Day

May June July Aug Sep

4 th July

Monday Feb 18 2013 9:28 PM

The ¡LHC@home ¡2.0 ¡project ¡Test4Theory ¡allows ¡users ¡to ¡par:cipate ¡in ¡running ¡ simula:ons ¡of ¡high-­‑energy ¡par:cle ¡physics ¡using ¡their ¡home ¡computers. The ¡results ¡are ¡submiAed ¡to ¡a ¡database ¡which ¡is ¡used ¡as ¡a ¡common ¡resource ¡by ¡both ¡ experimental ¡and ¡theore:cal ¡scien:sts ¡working ¡on ¡the ¡Large ¡Hadron ¡Collider ¡at ¡CERN.

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

Results → mcplots.cern.ch

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→ Constraints on model parameters

( To t a l n u m b e r o f p l o t s ~ 5 0 0 , 0 0 0 )

M C P L O T S

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SLIDE 11

The “Jeppsson” Project

April 2010

VINCIA

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

0.1 0.2 0.3 0.4 0.5

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1-T (udsc)

0.1 0.2 0.3 0.4 0.5

Theory/Data

0.6 0.8 1 1.2 1.4

Simulation 2 (too low) 1 = Experimental Measurement Result (yellow = uncertainty) Simultation 1 (too high)

Example: the effect of changing Vincia:alphaSvalue

“Thrust”: Measures how “spherical” events are

! * Strong-force Coupling Vincia:alphaSValue = 0.138 ! * Hadronic Energy Scale Vincia:cutoffScale = 0.45 ! * String parameters StringZ:aLund = 0.38 StringZ:bLund = 0.62 StringPT:sigma = 0.26 ! * Quark flavor parameters StringFlav:probStoUD = 0.21 StringFlav:mesonUDvector = 0.35 StringFlav:mesonSvector = 0.55 StringFlav:probQQtoQ = 0.08 StringFlav:probSQtoQQ = 1.00 StringFlav:probQQ1toQQ0 = 0.03 StringFlav:decupletSup = 1.00 StringFlav:etaSup = 0.60

The Jeppsson Project

April 2009: FB message from friend of friend: can a 15-yr

  • ld be a one-week intern

at CERN? We were developing a run- time display for our simulation anyway. April 2010: simple text editor to edit input cards. Run- time display to compare

  • utput histograms to data.

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

The Jeppsson Project

April 2009: FB message from friend of friend: can a 15-yr

  • ld be a one-week intern

at CERN? We were developing a run- time display for our simulation anyway. April 2010: simple text editor to edit input cards. Run- time display to compare

  • utput histograms to data.

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Mikkel Jeppsson Plots CERN April 2010

May 2010: Parameters released as new defaults.

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SLIDE 14

Atom Smashers

Starting May 2013

VINCIA

LHC Physics Center at CERN
  • The Citizen Cyberlab EU ICT Project - CERN’s Contribution
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  • P. Skands

Atom Smashers

The Citizen Cyberlab ICT Project

Standalone ¡3-­‑yr ¡Project ¡funded ¡by ¡EU ¡(2012-­‑2015)

CERN ¡Task: ¡create ¡ci7zen ¡science ¡pilot ¡project ¡in ¡par7cle ¡physics The ¡EU ¡funds ¡a ¡2-­‑year ¡“fellowship” ¡star7ng ¡in ¡May: ¡Ioannis ¡Charalimpidis

We ¡will

Develop ¡an ¡applica7on ¡that ¡lets ¡ci7zen ¡scien7sts ¡learn ¡about, ¡interact ¡with, ¡and ¡

  • p<mize ¡high-­‑energy ¡physics ¡simula<ons, ¡by ¡comparing ¡them ¡to ¡real ¡data

→ ¡feedback ¡to ¡scien7sts

How?

Combine ¡the ¡framework ¡and ¡lessons ¡from ¡Test4Theory ¡/ ¡LHC@home ¡2.0 ¡with ¡ those ¡from ¡the ¡Jeppsson ¡project ¡→ ¡Atom ¡Smasher ¡Applica<on Provide ¡content, ¡explana7ons, ¡visualiza7ons ¡(modifiable ¡and ¡open) Organize ¡one ¡or ¡more ¡ci<zen-­‑science ¡events ¡at ¡CERN ¡(e.g., ¡for ¡the ¡CERN ¡open ¡day ¡in ¡

September), ¡host ¡a ¡summer ¡student ¡(e.g., ¡a ¡4th ¡year ¡IT ¡or ¡Physics ¡student) ¡next ¡year, ¡… ¡

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

Structure

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  • 1. Immediately present user with

interesting and interactive content. Controls Display Task:

… … … … …

i i i i

Rollover tooltips + Click for more More detailed explanations can be clicked into → Explanation → Elaboration → Engagement

Controls are used to set the simulation parameters

Use the controls (left) to make the simulation agree with the data (right)

Level 1 Start simple:

  • ne physics

parameter and

  • ne

measurement.

Adjust

parameter to agree with measurement

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

Context Example

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Controls Display Controls

Are used to set the simulation

  • parameters. More elaboration … .

… … … … …

i i i i i i i

Level 1

  • 3. Users create their own annotations too (private / shared)

+ Combine with vote good/bad (incl our explanations) + Forums for further detailed discussion of issues

(divided into levels: citizens, phys students, experts)

  • 2. Provide deeper levels of context,

user extensions, and discussion Rollover tooltips + Click for more

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  • P. S k a n d s - C E R N - V i r t u a l C o l l i d e r s f o r C i t i z e n S c i e n t i s t s

Progress

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Controls Display

… … … … …

i i i i i i i

Level 23

(Ultimately → LHC)

  • 4. As user learns, unlock more distributions

& parameters (with explanations) Compare against current simulation defaults → feedback to scientists

i i i

Task:

Use the controls (left) to make the simulation agree with the data (right)

… …

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SLIDE 19

P e t e r S k a n d s : C E R N P i l o t P r o j e c t

What’s the Goal(s)?

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(visualization) : scientists also get a nice UI. It then needs to be close enough to the “real deal” that scientists can use it too.

Visual design (plots) must be professional and modifiable, usable in scientific publications. Bonus: can point to same graphics in real science papers

(citizen science) : beat the state of the art → feedback to scientists

Won’t happen every day, and not early. Contributing something real to the scientists is main motivator.

(learning) : people will learn about particle physics. Can also be used for outreach, and even for physics teaching

Progress markers may be useful, even desirable. How well am I doing? → Develop extra context layer (and targets) for university-level online course (for future)