HMLQCD

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Revision as of 17:15, 26 March 2012

General Information

• Application's name: Hadron Masses from Lattice QCD
• Application's acronym: HMLQCD
• Virtual Research Community: Computational Physics
• Scientific contact: Artan Boriçi
• Technical contact: Dafina Xhako, dafinaxhako@yahoo.com, Rudina Zeqirllari, rudina_mj@hotmail.com
• Developers: Dafina Xhako, Rudina Zeqirllari
• Web site: http://wiki.hp-see.eu/index.php/HMLQCD

Short Description

Lattice Quantum Chromodynamics (QCD) is the theory of strong interactions defined on four dimensional space-time hypercubic lattice. Its correlation functions are given by expectation values over path integrals. At present, the only direct tool to compute such integrals is the Markov Chain Monte Carlo method, which gives large autocorrelation times for certain observables. At any Markov step several huge and sparse linear systems have to be solved. Hence, the whole procedure results in a very expensive computational problem especially as the continuum limit is approached. The mass spectrum analysis involves computation of quark propagators, which are the solutions of huge linear systems of Dirac operators defined on the lattice. In order to converge, a typical Krylov subspace solver needs several hundreds or even thousands of multiplications by the lattice Dirac operator. The project idea is computation of basic properties of matter simulating the theory of strong interactions, Quantum Chromodynamic on the Lattice on massively parallel computers.

Our project aims to test for the first time local chiral actions for the calculation of the hadron masses. On the algorithmic side the project will test new solvers for overlap and domain wall fermions.

Problems Solved

Lattice QCD has become an indispensable tool both for particle and nuclear physics. The problems solved by the project are:

• Hadron spectrum computation
• Decay constants and comparison with chiral perturbation theory

Scientific and Social Impact

Solution of QCD has not been yet achieved. Our lattice study would like to complement other studies at different parameters and different lattice actions. Usage of local chiral fermions saves two orders of magnitude of computing resources. It gives physical results with unprecedented accuracy close to the chiral limit. Increased social support for scientific communities.

Collaborations

• TIRLatt (Tirana lattice QCD group)
• CaSToRC Institute, Cyprus, Greece

Beneficiaries

Main beneficiaries are research groups in Computational Physics. International lattice groups may benefit from expanded libraries of QCDLAB and of fermiQCD.

Number of users

2

Development Plan

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Resource Requirements

• Number of cores required: Limited to available number of CPUs
• Minimum RAM/core required: 1GB
• Storage space during a single run: 1-500GB
• Long-term data storage: 1TB
• Total core hours required: Unknown

Technical Features and HP-SEE Implementation

• Primary programming language: C/C++
• Parallel programming paradigm: MPI/Open MP
• Main parallel code: MPI
• Pre/post processing code: Own developer
• Application tools and libraries: FermiQCD, OpenMP

Usage Example

Infrastructure Usage

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Running on Several HP-SEE Centres

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Achieved Results

Publications

Foreseen Activities