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Title: Improved lattice computation of proton decay matrix elements

In this paper, we present an improved result for the lattice computation of the proton decay matrix elements in N f = 2 + 1 QCD. In this study, by adopting the error reduction technique of all-mode-averaging, a significant improvement of the statistical accuracy is achieved for the relevant form factor of proton (and also neutron) decay on the gauge ensemble of N f= 2 + 1 domain-wall fermions with m π = 0.34 – 0.69 GeV on a 2.7 fm 3 lattice, as used in our previous work. We improve the total accuracy of matrix elements to 10–15% from 30–40% for p → πe + or from 20–40% for p → K$$\bar{ν}$$. The accuracy of the low-energy constants α and β in the leading-order baryon chiral perturbation theory (BChPT) of proton decay are also improved. The relevant form factors of p → π estimated through the “direct” lattice calculation from the three-point function appear to be 1.4 times smaller than those from the “indirect” method using BChPT with α and β . It turns out that the utilization of our result will provide a factor 2–3 larger proton partial lifetime than that obtained using BChPT. Lastly, we also discuss the use of these parameters in a dark matter model.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Brookhaven National Lab. (BNL), Upton, NY (United States). RIKEN Research Center
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). RIKEN Research Center and High Energy Theory Group
  3. RIKEN Advanced Institute for Computational Science, Kobe (Japan)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States). High Energy Theory Group
Publication Date:
Report Number(s):
BNL-114705-2017-JA
Journal ID: ISSN 2470-0010; PRVDAQ; KA2401012
Grant/Contract Number:
SC0012704
Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 96; Journal Issue: 1; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; QCD; proton; decay; baryon; gluon; fermion; dark matter; chiral; perturbation
OSTI Identifier:
1413938