Daniele Alves

Tanmoy Bhattacharya

Michael L. Graesser

Rajan Gupta

#### Lattice QCD

The Los Alamos Lattice QCD team and their collaborators are carrying out precision studies investigating signatures of new physics at the TeV scale, Novel CP violating operator's contribution to nEDM, elucidating the structure of the nucleon, and neutrino-nucleon interactions. Progress during this quarter on these projects is described below. The team is also actively working on Quantum Information and Computing under the DOE call "Quantum Information Science Enabled Discovery For High Energy Physics".

Nucleon charges and form-factors

The analysis of isovector charges gA, gS and gT from the 2+1+1-flavor clover-on-HISQ calculations was completed and published in PRD. A paper describing the contribution of quark spin to the proton spin was published in PRD. A paper describing the calculation of the flavor diagonal tensor charges was also published in PRD. The analysis of electric, magnetic and axial vector form factors using up to 3-state fits for both the 2+1+1-flavor clover-on-HISQ and 2+1-flavor clover on clover lattice QCD formulations was carried out and manuscripts describing the results were worked on. Gupta is serving as a co-author on the FLAG 2019 review on nucleon matrix elements.

Matrix elements of novel CP violating operators and nEDM

Calculations of the matrix elements of the quark chromo electric dipole moment operator (cEDM) and mixing with the pseudoscalar operator are ongoing. Investigations of gradient flow method to deal with the divergent renormalization and mixing problem of the cEDM and Weinberg operators are continuing. Results presented at Lattice 2018 by Tanmoy Bhattacharya were written up for the conference proceedings.

Contributions from Disconnected diagrams

The matrix elements of flavor diagonal operators are needed for the analysis of a number of interesting qualities such as the nucleon electric dipole moment, the quark contribution to the nucleon spin, the nucleon sigma term and the strangeness content of the proton, and the interaction of dark matter with nucleons. These matrix elements also get contributions from disconnected diagrams, that are computationally challenging to compute with high precision. Bhattacharya, Gupta and Yoon published two manuscript describing the results of extensive simulations carried out over the last three years. These analyses included chiral and continuum extrapolation for the disconnected contribution of the flavor diagonal charges for the first time.

Transverse Momentum Distribution Functions

New simulations, in collaboration with the Regensburg group, are being done.

#### Dark Matter and LHC Physics

Graesser and UNM graduate student Jacek Osinski explored topological dark matter, in the form of hidden sector magnetic monopoles, produced in the early Universe during a second order phase transition. They generalized results in the prior literature by considering the impact of a non-standard cosmological history on the relic abundance of the monopoles. They found a monopole mass of order (1-100) PeV to be generic for the cosmological histories they considered, if monopoles are to entirely reproduce the current abundance of dark matter. Their results verify the robustness of the O(PeV) scale for the monopole mass that is needed if the early Universe is radiation-dominated around the time of production. A draft is in preparation.

Michael Graesser: Neutrinoless double beta decay

The neutrinoless double beta decay process (NDBD) is an important probe of any beyond-the-Standard-Model physics that violates lepton number by two units. NDBD provides a critical constraint on Majorana neutrino masses for active neutrinos, interactions of sterile/right-handed neutrinos, and on general classes of multi-TeV physics violating lepton number by two units. An important theoretical program is to use chiral effective theory to systematically describe how such high-energy physics, including Majorana neutrino masses, contribute to the NDBD process.

While there is the well-known long-range component of a Majorana neutrino mass to the NDBD matrix element, in Phys. Rev. Lett. 120 (2018) no.20, 202001, Graesser and collaborators found that there is also a short-range component. The numerical size of this new unknown low-energy constant (LEC) can only be computed using lattice QCD, but its size can be estimated in at least two ways. Non-perturbative renormalization of the long-range component -- which demonstrates a need for the new LEC -- also suggests the new contact interaction is suppressed only by $1/F^2_\pi$ rather than the nucleon mass$^2$, thereby providing a sizable effect on top of the long-range component. Next, the above reference shows that the LEC in NDBD is related to one of two LECs that describe charge and isospin breaking effects in nucleon scattering. The sizable charge and isospin breaking observed in nucleon-nucleon scattering lengths requires similarly large LECs, further suggesting that a large LEC occurs in NDBD.

He and his collaborators have now extended the above analysis in NDBD to next-leading-order in the chiral expansion, and a paper is in preparation.

Daniel S. M. Alves

During the past quarter, Daniele Alves has made progress on two projects: (1) models of sterile neutrinos with BSM interactions with matter via light mediators, specifically, on how these models are constrained by solar neutrinos, and how they could potentially address the distortion of the 8B solar neutrino spectrum, if confirmed; (2) generalizing Tensor Networks and Entanglement Renormalization to continuous effective field theories, specifically, using the Sine-Gordon/Thirring model as a testing ground for these methods.

Relevant References:
Journal of High Energy Physics 07 (2018) 92 arXiv:1710.03764

#### Lattice QCD

The Los Alamos Lattice QCD team and their collaborators are carrying out precision studies investigating signatures of new physics at the TeV scale, Novel CP violating operator's contribution to nEDM, elucidating the structure of the nucleon, and neutrino-nucleon interactions. Progress during this quarter on these projects is described below. The team is also actively working on Quantum Information and Computing under the DOE call "Quantum Information Science Enabled Discovery for High Energy Physics".

Nucleon charges and form-factors

The analysis of isovector and flavor diagonal charges, gA, gS and gT, from the 2+1+1-flavor clover-on-HISQ calculations was completed and results published in three papers in PRD. The analysis of electric, magnetic and axial vector form factors using up to 3-state fits for both the 2+1+1-flavor clover-on-HISQ and 2+1-flavor clover on clover lattice QCD formulations was carried out and manuscripts describing the results are in final stages of preparation. Gupta completed and submitted manuscripts for two plenary review talks at Spin 2018 and co-authored the FLAG 2019 review on nucleon matrix elements. The FLAG report was finalized and submitted for publication in this period.

Matrix elements of novel CP violating operators and nEDM

Calculations of the matrix elements of the quark chromo electric dipole moment operator (cEDM) and its mixing with the pseudoscalar operator, and of the Theta and Weinberg terms are on going. Preliminary results using a variance reduction method developed by us show a factor of ten reduction in errors. Investigations of gradient flow method to deal with the divergent renormalization and mixing problem of the cEDM and Weinberg operators are continuing.

Contributions from Disconnected diagrams

The matrix elements of flavor diagonal operators are needed for the analysis of a number of interesting qualities such as the nucleon electric dipole moment, the quark contribution to the nucleon spin, the nucleon sigma term and the strangeness content of the proton, and the interaction of dark matter with nucleons. These matrix elements also get contributions from disconnected diagrams, that are computationally challenging to compute with high precision. Bhattacharya, Gupta and Yoon published two manuscript describing the results (quark contribution to proton spin and neutron EDM) of extensive simulations carried out over the last three years. Developed the calculation of the renormalization factors needed for flavor diagonal operators. With these in hand, the analyses of disconnected contributions on five Wilson-clover ensembles have also been started.

Transverse Momentum Distribution Functions

New simulations, in collaboration with the Regensburg group, are continuing.

#### Dark Matter and LHC Physics

Graesser and UNM graduate student Jacek Osinski are finishing a manuscript on the impact that non-trivial cosmologies in the early history of the Universe may have on scenarios for topological dark matter. During this time period, Graesser started a new direction of research. He is investigating the constraints magnetars may place on axion and hidden sector monopole models for dark matter.

Michael Graesser: Neutrinoless double beta decay

Graesser continued his research into the neutrinoless double beta decay process nn-> pp ee, extending previous work to next-to-leading order in the chiral expansion. A manuscript is being completed. The neutrinoless double beta decay process (NDBD) is an important probe of any beyond-the-Standard-Model physics that violates lepton number by two units. NDBD provides a critical constraint on Majorana neutrino masses for active neutrinos, interactions of sterile/right-handed neutrinos, and on general classes of multi-TeV physics violating lepton number by two units. An important theoretical program is to use chiral effective theory to systematically describe how such high-energy physics, including Majorana neutrino masses, contribute to the NDBD process.

Daniel S. M. Alves
During the past quarter, Daniele Alves has worked on two projects: (1) extension of the neutrino sector to include sterile neutrinos interacting with matter via light mediators; exploration of these models to address short-baseline neutrino anomalies. (2) Extension of entanglement renormalization methods to continuous effective field theories; exploration of numerical implementations via wavelet transform techniques.

Relevant References:
Journal of High Energy Physics 07 (2018) 92 arXiv:1710.03764

#### Lattice QCD

The Los Alamos Lattice QCD team and their collaborators are carrying out precision studies investigating signatures of new physics at the TeV scale, Novel CP violating operator's contribution to nEDM, elucidating the structure of the nucleon, and neutrino-nucleon interactions. Progress during this quarter on these projects is described below. The team is also actively working on Quantum Information and Computing under the DOE call "Quantum Information Science Enabled Discovery For High Energy Physics".

Nucleon charges and form-factors

The analysis of isovector electric and magnetic form factors from the 2+1+1-flavor clover-on-HISQ calculations was completed and results published submitted for publication. The final analysis of and manuscript on axial vector form factors on these ensembles was started. Analysis of 2+1-flavor clover-on-clover lattice QCD calculations is in final stages and manuscripts describing the results are under preparation. Bhattacharya prepared and presented a plenary talk on "nucleon matrix elements" at Lattice 2019 and post-doc Sungwoo Park presented results on clover-on-clover calculations. Collaborator Yong-Chull presented results on isovector electric and magnetic form factors from the 2+1+1-flavor clover-on-HISQ calculations. Gupta prepared and presented a plenary review of axial and EM form factors at the Workshop on Lepton Interactions with Nucleans and Nuclei in Marciana Marina (Isola d'Elba), June 23-28, 2019.

Matrix elements of novel CP violating operators and nEDM

Calculations of the matrix elements of the quark chromo electric dipole moment operator (cEDM) and its mixing with the pseudoscalar operator, and of the Theta and Weinberg terms are on going. Preliminary results using a variance reduction method developed by us show a factor of ten reduction in errors. Investigations of gradient flow method to deal with the divergent renormalization and mixing problem of the cEDM and Weinberg operators are continuing. The status of our results were presented by Boram Yoon at Lattice 2019.

Contributions from Disconnected diagrams

The matrix elements of flavor diagonal operators are needed for the analysis of a number of interesting qualities such as the nucleon electric dipole moment, the quark contribution to the nucleon spin, the nucleon sigma term and the strangeness content of the proton, and the interaction of dark matter with nucleons. These matrix elements also get contributions from disconnected diagrams, that are computationally challenging to compute with high precision. This quarter, Bhattacharya, Gupta, Park and Yoon continued their analysis of the matrix elements of the scalar operator and their renormalization. These matrix elements are relevant for the sigma terms and dark matter interaction with nucleons.

Transverse Momentum Distribution Functions

New simulations, in collaboration with the Regensburg group, are being done.

#### Dark Matter and LHC Physics

Graesser and UNM graduate student Jacek Osinski are finishing a manuscript on the impact that non-trivial cosmologies in the early history of the Universe may have on scenarios for topological dark matter. He is investigating the constraints magnetars may place on axion-like particles. He is also exploring hidden sector monopole models for dark matter and their direct detection and astrophysical constraints. This work is in collaboration with Ian Shoemaker.

Michael Graesser: Neutrinoless double beta decay

Graesser continues his research into the neutrinoless double beta decay process nn-> pp ee, extending previous work to next-to-leading order in the chiral expansion. This work with his collaborators is will be posted at the end of July.

Daniel S. M. Alves

During the past quarter, Daniele Alves has continued to work on two projects: (1) extension of the neutrino sector to include sterile neutrinos interacting with matter via light mediators; exploration of these models to address short-baseline neutrino anomalies. (2) Extension of entanglement renormalization methods to continuous effective field theories; exploration of numerical implementations via wavelet transform techniques.

Relevant References:
Journal of High Energy Physics 07 (2018) 92 arXiv:1710.03764

#### Lattice QCD

The Los Alamos Lattice QCD team and their collaborators are carrying out precision studies investigating signatures of new physics at the TeV scale, Novel CP violating operator's contribution to nEDM, elucidating the structure of the nucleon, and neutrino-nucleon interactions. Progress during this quarter on these projects is summarized below.

Nucleon charges and form-factors

The analysis of isovector electric and magnetic form factors from the 2+1+1-flavor clover-on-HISQ calculations was completed and results were submitted for publication. A paper solving the problem of the violation of the partially conserved axial current by the axial form factors was prepared and submitted for publication. The final analysis of a manuscript on axial vector form factors on both 2+1+1-flavor clover-on-HISQ and 2+1-flavor clover-on-clover ensembles was carried out. Analysis of 2+1-flavor clover-on-clover lattice QCD calculations is in final stages and manuscripts describing the results are under preparation.

Matrix elements of novel CP violating operators and nEDM

Calculations of the matrix elements of the quark chromo electric dipole moment operator (cEDM) and its mixing with the pseudoscalar operator, and of the Theta and Weinberg terms are on going. Preliminary results using a variance reduction method developed by us show a factor of ten reduction in errors. Investigations of gradient flow method to deal with the divergent renormalization and mixing problem of the cEDM and Weinberg operators are continuing. The status of our results were presented by Boram Yoon at Lattice 2019.

Matrix elements of flavor diagonal operators

The matrix elements of flavor diagonal operators are needed for the analysis of a number of interesting qualities such as the nucleon electric dipole moment, the quark contribution to the nucleon spin, the nucleon sigma term and the strangeness content of the proton, and the interaction of dark matter with nucleons. These matrix elements get contributions from both connected and disconnected diagrams. The latter are computationally challenging to compute with high precision. This quarter, Bhattacharya, Gupta, Park and Yoon continued their analysis of the matrix elements of the scalar operator and their renormalization. These matrix elements are relevant for the sigma terms and dark matter interaction with nucleons.

Transverse Momentum Distribution Functions
New simulations, in collaboration with the Regensburg group, are continuing.

#### QuantISED

• Bhattacharya, Gupta and collaborators are developing methods to map continuum field theories onto a discrete space-time lattice with a small finite Hilbert space at each lattice site. They are currently determining whether the O(3) sigma model, represented by various O(3)-symmetric two-qubit Hamiltonian on each lattice site, displays desired properties such as confinement and topology. The long term goal is determine whether the sign problem and formulation of chiral gauge theories that are challenges for classical computers can be addressed by quantum computers. They are also developing algorithms for simulating qubit versions of field theories on quantum computers.
• Gupta and collaborators are developing quantum algorithms to understand the final states observed in the detector in a neutrino-nucleus interaction and connect it to the neutrino energy. This requires modelling the initial state (dominated by energy and distance scales of the order of the separation between nucleons in the nucleus) and the struck state and then evolve it quantum mechanically and calculate the response functions that encode information about the final states observed in the detectors. They are also exploring different error-mitigation techniques to increase the fidelity of the calculations. Details of the calculations and methodology are given in Ref. [1].
• Sorborger and collaborators are developing quantum algorithms for studying the foundations of quantum physics. Their algorithms will enable studies of the quantum-classical transition on near-term quantum computers and will extend the array of tools available to physicists for the study of system-environment interactions.
• Yoon, Bhattacharya, Gupta and collaborators are continuing to work on (1) enhancing lattice QCD calculations with the Machine Learning regression algorithm using the D-Wave quantum annealer, (2) developing a data compression algorithm on D-Wave and apply it to lattice QCD and Large Hadron Collider data, and (3) investigating various applications of the sparse coding implemented on D-Wave as a feature extraction algorithm that improves quantum support vector machine, generative models for lattice QCD Monte Carlo sampling and anomaly detector.

Publications:

Quantum Computing for Neutrino-nucleus Scattering, arXiv:1911.06368 (2019)

Machine-Learning Prediction for Quasi-PDF Matrix Elements, arXiv:1909.10990 (2019)

Physics Review D100 (2019) 054505: Qubit regularization of the O(3) sigma model

Physics Review D100 (2019) 014504: Machine Learning for Lattice QCD

Quantum simulations of one-dimensional quantum systems, R.D. Somma, Quantum Info. Comput. 16, 1125 (2016)

#### Michael Graesser: Dark Matter and LHC Physics

Graesser and University of New Mexico graduate student Jacek Osinski are finishing a manuscript on the impact that non-trivial cosmologies in the early history of the Universe may have on scenarios for topological dark matter. He is also investigating the constraints magnetars and other stellar objects may place on axion-like particles or other cosmological relics. He is also exploring hidden sector monopole models for dark matter and their direct detection and astrophysical constraints in collaboration with Ian Shoemaker.

#### Michael Graesser: Neutrinoless double beta decay

Graesser continues his research into the neutrinoless double beta decay process nn-> pp ee. A paper extending previous work to next-to-leading order in the chiral expansion has been published.

#### Daniel S. M. Alves

During the past quarter, Daniele has worked on the following topics:

• models of sterile neutrinos with BSM matter effects induced by light mediators, to explain the MiniBooNE low energy excess and the distortion in the 8B solar neutrino spectrum. She is currently investigating whether this model might also explain the LSND anomaly;
• new 40Ar disintegration signatures of light axions and dark photons at CCM, and estimation of CCM sensitivity to uncovered parameter space in this models;
• axion interactions with monopoles, and possible realization of these interactions in condensed matter systems, such as spin ice;
• investigation of whether the anomalies in 8Be and 4He transitions can be tested with a new experiment hosted at LANL;
• preparation of a new paper on future experimental constraints on a pion-phobic QCD axion in the MeV mass window;
• a new implementation of the renormalization group in EFTs in position space, by generalizing methods of entanglement renormalization and tensor networks from CMP and QIS.

Relevant References:
Journal of High Energy Physics 07 (2018) 92 arXiv:1710.03764