S-Matrix and the Grid
Geoffrey Fo
Professor of Computer Science, Informatics, Physics Pervasive Technology Laboratories
Indiana University Bloomington IN 47401 December 12 2003
S-Matrix and PWA
n We need an amplitude analysis to find most “interesting” resonances n If this makes sense, we are effectively parameterizing photon-Reggeon
amplitude with resonance at “top” vertex in full (123 in diagram) or partial (12, 23, 31) channel
• Complicated as off diagonal, one “fake” particle and often more
than 2 final particles
n This requires a lot of approximations whose effect can be estimated
with S-Matrix Theory
• Analyticity, Unitarity, Crossing, Regge Theory, Spin formalism,
Duality, Finite Energy Sum Rules
1
2
3
Reggeon Exchange fo
Production
Exchang e
Target
Some Lessons from the past I
n All confusing effects exist and no fundamental (correct) way to
remove. So one should:
• Minimize effect of the hard (insoluble) problems such as
“particles from wrong vertex”, “unestimatable exchange effects” sensitive to slope of unclear Regge trajectories, absorption etc.
• Carefully identify where effects are “additive” and where
confusingly overlapping
n Note many of effects are intrinsically MORE important in
multiparticle case than in relatively well studied π N π N
n Try to estimate impact of uncertainties from each effect on results
• It would be very helpful to get systematic very high statistic
studies of relatively clean cases where spectroscopy may be less interesting but one can examine uncertainties
• Possibilities are A1 A2 A3 B1 peripherally produced and even π
S-Matrix Approach
n
S-Matrix ideas that work reasonably include:
n
Regge
theory for
production
process
n
Two-component duality
adding Regge dual to Regge to
background dual to the Pomeron
• Can help to identify if a resonance is classic qq or exotic
n
Use of Regge exchange at top vertex to estimate
high
partial waves
in amplitude analysis
n
Finite Energy Sum Rules
for top vertex as constraints
on low mass amplitudes and most quantitative way of
linking high and low masses
n
Ignore
Regge Cuts
in Production
n
Unitarity
effects not included directly due to duality
Investigate Uncertainties
n There are several possible sources of error
• Errors in Quasi 2-body and limited number of amplitudes
approximation
• Unitarity (final state interactions)
• Errors in the two-component duality picture
• Exotic particles are produced and are just different
• Photon beams, π exchange or some other “classic effect” not
present in original πN analyses behaves unexpectedly
• Failure of quasi two body approximation • Regge cuts cannot be ignored
• Background from other channels
n Develop tests for these in both “easy” cases (such as “old” meson
beam data) and in photon beam data at Jefferson laboratory
Grid Computing: Making The Global
Infrastructure a Reality
n Note book wit
Fran Berman an
Anthony J.G. Hey,
n ISBN: 0-470-85319-0 n Hardcover 1080 Pages n Published March 2003 n http://www.grid2002.org
n I had more fun in days gone by; no
more do I write
n “Skeletons in the Regge
Cupboard” or
n “The Importance of being an
Some Further Links
n
A talk on Grid and e-Science was webcast in an
Oracle
technology serie
http://webevents.broadcast.com/techtarget/Oracle/100303/index.asp?loc=10
n
See
also the “
Gap Analysis
” survey of Grid technolog
http://grids.ucs.indiana.edu/ptliupages/publications/GapAnalysis30June03v2.pdf
n
This p
resentation
is at
http:/
/grids.ucs.indiana.edu/ptliupages/presentations
n
Next Se
mester – course on “
e-Science and the Grid
”
given by Access Grid
n
Write up for May Conference describes proposed
Physics Strateg
e-Business e-Science and the Grid
n
e-Business
captures an emerging view of corporations as
dynamic
virtual organizations
linking employees, customers
and stakeholders across the world.
•
The growing use of
outsourcing
is one example
n
e-Science
is the similar vision for scientific research with
international participation in large accelerators, satellites or
distributed gene analyses.
n
The
Grid
integrates the best of the Web, traditional
enterprise software, high performance computing and
Peer-to-peer systems to provide the information technology
infrastructure for
e-moreorlessanything.
n
A
deluge of data
of unprecedented and inevitable size must
be managed and understood.
n
People,
computers,
data
and
instruments
must be linked.
n
On demand
assignment of experts, computers, networks and
What is a High Performance Computer?
n We might wish to consider three classes of multi-node computers n 1) Classic MPP with microsecond latency and scalable internode
bandwidth (tcomm/tcalc ~ 10 or so)
n 2) Classic Cluster which can vary from configurations like 1) to 3)
but typically have millisecond latency and modest bandwidth
n 3) Classic Grid or distributed systems of computers around the
network
• Latencies of inter-node communication – 100’s of milliseconds
but can have good bandwidth
n All have same peak CPU performance but synchronization costs
increase as one goes from 1) to 3)
n Cost of system (dollars per gigaflop) decreases by factors of 2 at
each step from 1) to 2) to 3)
n One should NOT use classic MPP if class 2) or 3) suffices unless
some security or data issues dominates over cost-performance
n One should not use a Grid as a true parallel computer – it can
Sources of Grid Technology
n
Grids support distributed collaboratories or virtual
organizations integrating concepts from
n
The Web
n
Agents
n
Distributed Objects
(CORBA Java/Jini COM)
n
Globus, Legion, Condor, NetSolve, Ninf and other High
Performance Computing activities
n
Peer-to-peer Networks
n
With perhaps the Web and P2P networks being the most
important for “Information Grids” and Globus for
“Compute Grids”
n
Service Architecture based on
Web Services
most
A typical Web Service
n In principle, services can be in any language (Fortran .. Java ..
Perl .. Python) and the interfaces can be method calls, Java RMI Messages, CGI Web invocations, totally compiled away (inlining)
n The simplest implementations involve XML messages (SOAP) and
programs written in net friendly languages like Java and Python
Paymen Credit
Card
Warehous e
Shipping WSDL
interfaces WSDL interfaces
Securit
y Catalog
Porta Service
What is Happening?
n
Grid ideas are being developed in (at least) two
communities
• Web Service – W3C, OASIS
• Grid Forum (High Performance Computing, e-Science)
n
Service
Standards
are being debated
n
Grid Operational
Infrastructure
is being deployed
n
Grid Architecture
and core software being developed
n
Particular
System Services
are being developed
“centrally” – OGSA framework for this in
n
Lots of fields are setting
domain specific standards
and
building domain specific
services
n
There is a lot of
hype
n
Grids are viewed differently in different areas
• Largely “computing-on-demand” in industry (IBM, Oracle,
HP, Sun)
Technical Activities of Note
n
Look at different styles of Grids such as
Autonomic
(Robust
Reliable Resilient)
n
New Grid architectures hard due to investment required
nCritical
Services
Such as
•
Security
– build message based not connection based
•Notification
– event services
•
Metadata
– Use Semantic Web, provenance
•
Databases and repositories
– instruments, sensors
•Computing
– Submit job, scheduling, distributed file
systems
•
Visualization, Computational Steering
•Fabric
and Service Management
•
Network
performance
n
Program
the Grid – Workflow
Issues and Types of Grid Services
n 1) Types of Grid
• R3
• Lightweight • P2P
• Federation and Interoperability
n 2) Core Infrastructure and Hosting
Environment
• Service Management • Component Model
• Service wrapper/Invocation • Messaging
n 3) Security Services
• Certificate Authority • Authentication
• Authorization • Policy
n 4) Workflow Services and Programming
Model
• Enactment Engines (Runtime) • Languages and Programming • Compiler
• Composition/Development
n 5) Notification Services
n 6) Metadata and Information Services
• Basic including Registry
• Semantically rich Services and
meta-data
• Information Aggregation (events) • Provenance
n 7) Information Grid Services
• OGSA-DAI/DAIT
• Integration with compute resources • P2P and database models
n 8) Compute/File Grid Services
• Job Submission
• Job Planning Scheduling
Management
• Access to Remote Files, Storage and
Computers
• Replica (cache) Management • Virtual Data
• Parallel Computing
n 9) Other services including
• Grid Shell • Accounting
• Fabric Management
• Visualization Data-mining and
Computational Steering
• Collaboration
n 10) Portals and Problem Solvin
Environments
n 11) Network Services
OGSA OGSI & Hosting
Environments
n Start with Web Services in a hosting environment
n Add OGSI to get a Grid service and a component model
n Add OGSA to get Interoperable Grid “correcting” differences in base platform
and adding key functionalities
OGSI on Web Services
Broadly applicable services: registry,
authorization, monitoring, data
access, etc., etc.
Hosting Environment for
More specialized services: data
replication, workflow, etc., etc. Domai
n - servicesspecific
OGSA
Environment
Integration of Data and Filters
n
One has the OGSA-DAI Data repository interface
combined with WSDL of the (Perl, Fortran,
Python …) filter
n
User only sees WSDL not data syntax
n
Some non-trivial issues as to where the filtering
compute power is
• Microsoft says filter next to data
D B
Filter WSDL
Of Filter
Data
Technology Components of (Services in
1: Job Management Service
(Grid Service Interface to user or program client)
2: Schedule and control Execution
1: Plan
Execution Submittal4: Job
Remote Grid Service Remote Grid
Service
6: File and Storage
Access
3: Access to Remote Computers
Data
7: Cach Dat
Replicas 5: Data Transfer
10: Job Status
Grid Strategy
n
LHC Computing will be very well established and
handling 10-100 times as much data as GlueX when we
need to go into production
n
GriPhyn iVDGL EDG EGEE PPDG GridPP will
customize core Grid technology for accelerator-based
experiments
• Transport Data • Cache Data
• Manage initial data analysis and Monte Carlo
n
Not clear if GT2, GT3, OGSI but will certainly be Web
Service based
n
Need to keep in close touch with these activities
nBuild GlueX physics analysis consistent with this
Implementing Grids
n
Need to design a
service architecture
for GlueX
•
Build on services from HEP and other fields
•
Need some specific
gluexML
meta-data specifying services
and properties specific to GlueX
•
Specify data structures and method interfaces in XML
n
Use portlets for user-interfaces as in http
://www.ogce.org
nBre
ak-up into
services
where-ever possible but only if
“coarse-grain”
Module A Module
B
Method Call
Service A Service
B Messages
0.1 to 1000 millisecond
Coarse Grain Service Model
Collage of Portals
Earthquakes – NAS Fusion – DoE
Approach
n
Convert every code into a Web Service
n
Convert every utility like
“visualization” into a Web service
n
Have good support for authoring and
manipulating meta-data
n
Use existing code/database technology
(SQL/Fortran/C++) linked to “Application
Web/OGSA services”
•
XML specification of models,
computational steering, scale supported
at “Web Service” level as don’t need
“high performance” here
•
Allows use of Semantic Grid technology
Typica codes
WS linking to user and
Other WS (data sources)
