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X-WR-CALNAME:Centre for Mathematical Sciences
X-ORIGINAL-URL:http://math-sciences.org
X-WR-CALDESC:Events for Centre for Mathematical Sciences
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TZOFFSETFROM:+0000
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DTSTART:20130101T000000
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DTSTART;TZID=UTC:20131113T160000
DTEND;TZID=UTC:20131113T170000
DTSTAMP:20230528T203614
CREATED:20151210T234321Z
LAST-MODIFIED:20151211T163429Z
UID:327-1384358400-1384362000@math-sciences.org
SUMMARY:Antonin Portelli (Southampton)
DESCRIPTION:Isospin breaking effects from lattice QCD and QED\nIsospin symmetry is explicitly broken in the Standard Model by the non-zero differences of mass and electric charge between the up and down quarks. Both of these corrections are expected to have a comparable size of the order of one percent relatively to hadronic energies. Although these contributions are small\, they play a crucial role in hadronic and nuclear physics. For example\, the neutron-proton mass difference is responsible for the stability of the hydrogen atom and it is an important initial condition of Big-Bang nucleosynthesis. Even if these effects are well known experimentally\, a theoretical determination from first principles is still an open problem because of the non-perturbative nature of low-energy QCD.\nIn this talk I will present a way to include isospin breaking effects in lattice QCD simulation in order to perform ab-initio computations of isospin mass splittings. The main challenge is to formulate the electromagnetic interaction on a finite and periodic lattice and to couple it to lattice QCD. Finally\, I will present the results of the Budapest-Marseille-Wuppertal collaboration for the octet baryon mass splittings and the individual up and down quark masses.
URL:http://math-sciences.org/event/antonin-portelli-southampton/
LOCATION:Room 205\, 2-5\, Kirkby Place\, Plymouth\, PL4 6DT\, United Kingdom
CATEGORIES:Seminars,Theoretical Physics
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