Hadronic Matrix Elements and Weak Decays in Lattice QCD

1990 ◽  
pp. 239-295
Author(s):  
Guido Martinelli
Keyword(s):  
Lattice Qcd ◽  
Matrix Elements ◽  
Weak Decays

scholarly journals Double parton distributions in the pion from lattice QCD

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Gunnar S. Bali ◽  
Luca Castagnini ◽  
Markus Diehl ◽  
Jonathan R. Gaunt ◽  
Benjamin Gläßle ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Lattice Qcd ◽  
Quark Mass ◽  
Matrix Elements ◽  
Parton Distributions ◽  
Almost All ◽  
The Relationship

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.

scholarly journals Light-cone sum rules for proton decay

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ulrich Haisch ◽  
Amando Hala
Keyword(s):  
Lattice Qcd ◽  
Light Cone ◽  
Sum Rules ◽  
State Of The Art ◽  
Form Factors ◽  
Baryon Number ◽  
Proton Decay ◽  
Matrix Elements ◽  
Decay Channels ◽  
Systematic Uncertainties

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.

INDICATIONS OF A ΔI=1/2 RULE IN THE STRONG COUPLING REGIME

1988 ◽  
Vol 03 (06) ◽  
pp. 1385-1412
Author(s):  
IAN G. ANGUS
Keyword(s):  
Lattice Qcd ◽  
Strong Coupling ◽  
Computer Algebra ◽  
Free Parameter ◽  
Hamiltonian Formalism ◽  
Strong Coupling Expansion ◽  
Calculation Scheme ◽  
Strong Coupling Regime ◽  
Weak Decays ◽  
The One

We will attempt to understand the ΔI=1/2 pattern of the nonleptonic weak decays of the kaons. The calculation scheme employed is the Strong Coupling Expansion of lattice QCD. Kogut-Susskind fermions are used in the Hamiltonian formalism. We will describe in detail the methods used to expedite this calculation, all of which was done by computer algebra. The final result is very encouraging. Even though an exact interpretation is clouded by the presence of irrelevant operators, and questions of lattice artifacts, a signal of the ΔI=1/2 rule appears to be observable. With an appropriate choice of the one free parameter, enhancements greater than those observed experimentally can be obtained. We also point out a number of surprising results which we turn up in the course of the calculation.

scholarly journals Electroweak matrix elements in the two-nucleon sector from lattice QCD

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

scholarly journals Neutron Electric Dipole Moment on the Lattice

2018 ◽  
Vol 175 ◽  
pp. 01014 ◽  
Author(s):  
Boram Yoon ◽  
Tanmoy Bhattacharya ◽  
Rajan Gupta
Keyword(s):  
Dipole Moment ◽  
Cp Violation ◽  
Lattice Qcd ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Beyond The Standard Model ◽  
Matrix Elements ◽  
The Standard Model ◽  
The Status ◽  
Good Probe

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.

scholarly journals QCD Factorization and PDFs from Lattice QCD Calculation

2015 ◽  
Vol 37 ◽  
pp. 1560041 ◽  
Author(s):  
Yan-Qing Ma ◽  
Jian-Wei Qiu
Keyword(s):  
Euclidean Space ◽  
Minkowski Space ◽  
Lattice Qcd ◽  
Correlation Functions ◽  
Parton Distribution ◽  
Distribution Functions ◽  
Matrix Elements ◽  
Parton Distribution Functions ◽  
Qcd Factorization ◽  
The Matrix

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.

scholarly journals Lifetimes and heavy quark expansion

2015 ◽  
Vol 30 (10) ◽  
pp. 1543005 ◽  
Author(s):  
Alexander Lenz
Keyword(s):  
Heavy Quark ◽  
Experimental Tests ◽  
Heavy Quarks ◽  
Experimental Results ◽  
Current Status ◽  
Matrix Elements ◽  
Weak Decays ◽  
The Subject

Kolya Uraltsev was one of the inventors of the Heavy Quark Expansion (HQE), that describes inclusive weak decays of hadrons containing heavy quarks and in particular lifetimes. Besides giving a pedagogic introduction to the subject, we review the development and the current status of the HQE, which just recently passed several non-trivial experimental tests with an unprecedented precision. In view of many new experimental results for lifetimes of heavy hadrons, we also update several theory predictions: [Formula: see text], τ(Bs)/τ(Bd) = 1.001 ±0.002, τ(Λb)/τ(Bd) = 0.935 ±0.054 and [Formula: see text]. The theoretical precision is currently strongly limited by the unknown size of the non-perturbative matrix elements of four-quark operators, which could be determined with lattice simulations.

scholarly journals Nucleon matrix elements from lattice QCD with all-mode-averaging and a domain-decomposed solver: An exploratory study

2017 ◽  
Vol 914 ◽  
pp. 138-159 ◽  
Author(s):  
Georg von Hippel ◽  
Thomas D. Rae ◽  
Eigo Shintani ◽  
Hartmut Wittig
Keyword(s):  
Lattice Qcd ◽  
Exploratory Study ◽  
Matrix Elements

scholarly journals Study on theΥ(1S)→BcMWeak Decays

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Junfeng Sun ◽  
Lili Chen ◽  
Na Wang ◽  
Qin Chang ◽  
Jinshu Huang ◽  
...  
Keyword(s):  
Branching Ratio ◽  
Heavy Flavor ◽  
Matrix Elements ◽  
High Luminosity ◽  
Weak Decays ◽  
The Future

Motivated by the prospects of the potentialΥ(1S)particle at high-luminosity heavy-flavor experiments, we studied theΥ(1S)→BcMweak decays, whereM=π,ρ,K(∗). The nonfactorizable contributions to hadronic matrix elements are taken into consideration with the QCDF approach. It is found that the CKM-favoredΥ(1S)→Bcρdecay has branching ratio ofO(10-10), which might be measured promisingly by the future experiments.

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