Proton decay matrix elements with domain-wall fermions

Abstract We estimate the form factors that parametrise the hadronic matrix elements of proton-to-pion transitions with the help of light-cone sum rules. These form factors are relevant for semi-leptonic proton decay channels induced by baryon-number violating dimension-six operators, as typically studied in the context of grand unified theories. We calculate the form factors in a kinematical regime where the momentum transfer from the proton to the pion is space-like and extrapolate our final results to the regime that is relevant for proton decay. In this way, we obtain estimates for the form factors that show agreement with the state-of-the-art calculations in lattice QCD, if systematic uncertainties are taken into account. Our work is a first step towards calculating more involved proton decay channels where lattice QCD results are not available at present.

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Nucleon distribution amplitudes and proton decay matrix elements on the lattice

Physical Review D ◽

10.1103/physrevd.79.034504 ◽

2009 ◽

Vol 79 (3) ◽

Cited By ~ 33

Author(s):

Vladimir M. Braun ◽

Meinulf Göckeler ◽

Roger Horsley ◽

Thomas Kaltenbrunner ◽

Yoshifumi Nakamura ◽

...

Keyword(s):

Proton Decay ◽

Matrix Elements

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Construction of lattice Möbius domain wall fermions in the Schrödinger functional scheme

International Journal of Modern Physics A ◽

10.1142/s0217751x18500124 ◽

2018 ◽

Vol 33 (01) ◽

pp. 1850012

Author(s):

Yuko Murakami ◽

Ken-Ichi Ishikawa

Keyword(s):

Perturbation Theory ◽

Gauge Theory ◽

Domain Wall ◽

Beta Function ◽

Boundary Operator ◽

Tree Level ◽

Domain Wall Fermions ◽

Functional Scheme ◽

Temporal Boundary ◽

Optimal Type

In this paper, we construct the Möbius domain wall fermions (MDWFs) in the Schrödinger functional (SF) scheme for the SU(3) gauge theory by adding a boundary operator at the temporal boundary of the SF scheme setup. Using perturbation theory, we investigate the properties of several constructed MDWFs, including the optimal type domain wall, overlap, truncated domain wall, and truncated overlap fermions. We observe the universality of the spectrum of the effective four-dimensional operator at the tree-level, and fermionic contribution to the universal one-loop beta function is reproduced for MDWFs with a sufficiently large fifth-dimensional extent.

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