scholarly journals Matrix elements relevant forΔI=1/2rule andɛ′/ɛ from lattice QCD with staggered fermions

2001 ◽  
Vol 64 (7) ◽  
Author(s):  
D. Pekurovsky ◽  
G. Kilcup
2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Gunnar S. Bali ◽  
Luca Castagnini ◽  
Markus Diehl ◽  
Jonathan R. Gaunt ◽  
Benjamin Gläßle ◽  
...  

Abstract We perform a lattice study of double parton distributions in the pion, using the relationship between their Mellin moments and pion matrix elements of two local currents. A good statistical signal is obtained for almost all relevant Wick contractions. We investigate correlations in the spatial distribution of two partons in the pion, as well as correlations involving the parton polarisation. The patterns we observe depend significantly on the quark mass. We investigate the assumption that double parton distributions approximately factorise into a convolution of single parton distributions.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ulrich Haisch ◽  
Amando Hala

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.


2004 ◽  
Vol 743 (1-3) ◽  
pp. 170-193 ◽  
Author(s):  
William Detmold ◽  
Martin J. Savage
Keyword(s):  

2020 ◽  
Vol 101 (7) ◽  
Author(s):  
M. Giordano ◽  
K. Kapas ◽  
S. D. Katz ◽  
D. Nogradi ◽  
A. Pasztor

2018 ◽  
Vol 175 ◽  
pp. 01014 ◽  
Author(s):  
Boram Yoon ◽  
Tanmoy Bhattacharya ◽  
Rajan Gupta

For the neutron to have an electric dipole moment (EDM), the theory of nature must have T, or equivalently CP, violation. Neutron EDM is a very good probe of novel CP violation in beyond the standard model physics. To leverage the connection between measured neutron EDM and novel mechanism of CP violation, one requires the calculation of matrix elements for CP violating operators, for which lattice QCD provides a first principle method. In this paper, we review the status of recent lattice QCD calculations of the contributions of the QCD Θ-term, the quark EDM term, and the quark chromo-EDM term to the neutron EDM.


Author(s):  
Yan-Qing Ma ◽  
Jian-Wei Qiu

In this talk, we review a QCD factorization based approach to extract parton distribution and correlation functions from lattice QCD calculation of single hadron matrix elements of quark-gluon operators. We argue that although the lattice QCD calculations are done in the Euclidean space, the nonperturbative collinear behavior of the matrix elements are the same as that in the Minkowski space, and could be systematically factorized into parton distribution functions with infrared safe matching coefficients. The matching coefficients can be calculated perturbatively by applying the factorization formalism on to asymptotic partonic states.


1987 ◽  
Vol 286 ◽  
pp. 253-292 ◽  
Author(s):  
Stephen R. Sharpe ◽  
Apoorva Patel ◽  
Rajan Gupta ◽  
Gerald Guralnik ◽  
Gregory W. Kilcup

2017 ◽  
Vol 914 ◽  
pp. 138-159 ◽  
Author(s):  
Georg von Hippel ◽  
Thomas D. Rae ◽  
Eigo Shintani ◽  
Hartmut Wittig

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