Daniele Alves

Tanmoy Bhattacharya

Michael L. Graesser

Rajan Gupta

Michael S. Warren

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 understanding QCD at finite temperature. Progress during this quarter on these projects is described below.

 

Nucleon charges and form-factors

Extensive additional simulations of isovector and flavor-diagonal charges gA, gS and gT from the 2+1+1-flavor clover-on-HISQ calculations were completed, including the analysis of the very time consuming second physical mass HISQ ensemble with lattice size 963 ×192 at 0.06 fm on cluster and GPU computers at Los Alamos and using ERCAP allocations at NERSC. The final analysis of nucleon charges, 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 is ongoing and five manuscripts describing the results are being prepared. Preliminary results were presented by Rajan Gupta and Yong-Chull Jang at Lattice 2017, and the write ups accepted for publication as part of the conference proceedings. Our first results for the axial vector form factors from 2+1+1-flavor clover-on-HISQ have been published in PRD.

Relevant References:
Physical Review D96 (2017) 114503 arXiv:1705.06834
Physical Review D95:5 (2017) 074508
Physical Review D94:5 (2016) 054508
Physical Review D93:11 (2016) 114506
arXiv:1601.01730
Physical Review D92:9 (2015) 094511
Physical Review D89:9 (2014) 094502
Physical Review D85:5 (2012) 054512

 

Matrix elements of novel CP violating operators and nEDM

Calculations of the matrix elements of the quark chromo electric dipole moment operator and mixing with the pseudoscalar operator are ongoing. The formalism for these calculations and new numerical techniques are being developed. Status of results was presented at Lattice 2017 by Boram Yoon in a plenary talk titled "neutron electric moment on the lattice".

Relevant References:
arXiv:1712.08557
arXiv:1701.04132
arXiv:1612.08438
arXiv:1601.02264
Physical Review D92:9 (2015) 114026
Physical Review Letters 112:21 (2015) 212002
arXiv:1502.07325
arXiv:1403.2445
arXiv:1212.4918

 

Disconnected diagrams

The matrix elements of iso-scalar and flavor diagonal operators are needed for the analysis of a number of interesting qualities such as the nucleon electric dipole moment, 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 disconnected diagrams, that are computationally challenging to compute with high precision. Bhattacharya, Gupta and Yoon are preparing a manuscript describing the results of extensive simulations carried out over the last three years for publication. In these calculations they analyze the chiral and continuum extrapolation for the flavor diagonal charges for the first time. They are also collaborating with Gambhir, Orginos and Stathopoulos at William and Mary to develop a new method based on deflation and hierarchical probing to speed up the calculation of disconnected diagrams.

Relevant References:
arXiv:1611.01193

 

Transverse Momentum Distribution Functions

Results for the Sivers and Boer-Mulders shift, the transversity and the generalized worm-gear shift for two different fermion discretization schemes were finalized and published in PRD [arXiv:1706.03406].

Relevant References:
Physical Review D96 (2017) 094508 arXiv:1706.03406
arXiv:1611.01193
arXiv:1601.05717

 

Behavior of QCD at finite temperature

Investigated the properties of QCD at finite temperature, including the nature of the transition, the equation of state and the fluctuations of conserved charges (electric charge, strangeness, baryon number) around the transition temperature (140–160 MeV) as part of the HOTQCD collaboration. The five publications have over 2100 citations.

Relevant References:
Physical Review D90 (2014) 094503
Physical Review Letters 113 (2014) 082001
Physical Review D86 (2012) 034509
Physical Review D86 (2012) 094503
Physical Review D85 (2012) 054503

 

Dark Matter and LHC Physics

Graesser is revisiting the topological dark matter scenario and generalizing it in several directions. He is also continuing his work with Tuhin Roy (TATA) and Arun Thalapillil (Pune) on improving the sensitivity of the LHC to new TeV-scale physics scenarios.

Relevant References:
Physics Letters B749 (2014) 293
arXiv:1311.2028
Physical Review Letters111 (2013) 121802
JHEP 1302(2013) 046
JHEP 1210(2012) 025
Physics Letters B714 (2012) 267
Physics Review D85 (2012) 054512
arXiv:1107.2666
JHEP 1110(2011) 110

 

Neutrinoless double beta decay

Graesser, together with Cirigliano, Dekens and Mereghetti (LANL) and de Vries (Niken), has obtained a master formula for the neutrinoless double beta decay rate caused by the standard neutrino mass mechanism as well as dimension-9 lepton violating operators.

Graesser, Cirigliano, Dekens, de Vries, van Kolck, Mereghetti, and Pastore, are investigating the leading order ladder-diagram resummation (a la Kaplan, Savage and Wise (KSW)) of the standard neutrino mass contribution to the neutrinoless double beta decay amplitude, in the nn-> pp ee S10 channel, due to loops of pions and four-nucleon contact operators.

Relevant References:
Journal of High Energy Physics12 (2017) 82 arXiv:1708.09390
Journal of High Energy Physics (2017)99
Physics Letters B769 (2017) 460

 

MeV Axions and New Physics at the GeV Scale

Daniele S. M. Alves is working on follow-ups to her work on MeV axions and New Physics at the GeV scale (arXiv:1710.03764; submitted to JHEP). She is currently focused on exploring "hadron impostors", i.e., BSM states at the GeV scale that couple hadronically. These states might have evaded discovery due to large hadronic backgrounds, or might have been seen but were misinterpreted as hadronic resonances. She is also deriving new constraints on MeV axions.

Relevant References:
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 understanding QCD at finite temperature. Progress during this quarter on these projects is described below. The team spent considerable time working on Quantum Information and Computing and are PI/members of four proposals responding to the DOE call "Quantum Information Science Enabled Discovery For High Energy Physics" was developed and submitted. 

 

Nucleon charges and form-factors

Extensive additional simulations of isovector and flavor-diagonal charges gA, gS and gT from the 2+1+1-flavor clover-on-HISQ calculations were completed, including the analysis of the very time consuming second physical mass HISQ ensemble with lattice size 963 ×192 at 0.06 fm on cluster and GPU computers at Los Alamos and using ERCAP allocations at NERSC. The final analysis of nucleon charges, 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 is almost complete and five manuscripts describing the results are in final draft form. Preliminary results, presented by Rajan Gupta and Yong-Chull Jang at Lattice 2017, have been published as part of the conference proceedings. First results for the axial vector form factors from 2+1+1-flavor clover-on-HISQ have been published in PhysRevD.96.114503.

Relevant References:
Physical Review D96 (2017) 114503 arXiv:1705.06834
Physical Review D95:5 (2017) 074508
Physical Review D94:5 (2016) 054508
Physical Review D93:11 (2016) 114506
arXiv:1601.01730
Physical Review D92:9 (2015) 094511
Physical Review D89:9 (2014) 094502
Physical Review D85:5 (2012) 054512

 

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. The formalism for these calculations and new numerical techniques are being developed. Status of results was presented at Lattice 2017 by Boram Yoon in a plenary talk titled "neutron electric moment on the lattice". The gradient flow method for controlling the mixing and renormalizing issues for the cEDM operator is being investigated.

Relevant References:
arXiv:1712.08557
arXiv:1701.04132
arXiv:1612.08438
arXiv:1601.02264
Physical Review D92:9 (2015) 114026
Physical Review Letters 112:21 (2015) 212002
arXiv:1502.07325
arXiv:1403.2445
arXiv:1212.4918

 

Disconnected diagrams

The matrix elements of iso-scalar and flavor diagonal operators are needed for the analysis of a number of interesting qualities such as the nucleon electric dipole moment, 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 disconnected diagrams, that are computationally challenging to compute with high precision. Bhattacharya, Gupta and Yoon worked on the draft manuscript describing the results of extensive simulations carried out over the last three years for publication. In these calculations they analyze the chiral and continuum extrapolation for the flavor diagonal charges for the first time. They are continuing to collaborate with Gambhir, Orginos and Stathopoulos at William and Mary to develop a new method based on deflation and hierarchical probing to speed up the calculation of disconnected diagrams.

Relevant References:
arXiv:1611.01193

 

Transverse Momentum Distribution Functions

Results for the Sivers and Boer-Mulders shift, the transversity and the generalized worm-gear shift for two different fermion discretization schemes were finalized and published in PRD [arXiv:1706.03406]. New simulations, in collaboration with the Regensburg group, have been initiated.

Relevant References:
Physical Review D96 (2017) 094508 arXiv:1706.03406
arXiv:1611.01193
arXiv:1601.05717

 

Behavior of QCD at finite temperature

Investigated the properties of QCD at finite temperature, including the nature of the transition, the equation of state and the fluctuations of conserved charges (electric charge, strangeness, baryon number) around the transition temperature (140–160 MeV) as part of the HOTQCD collaboration. The five publications have over 2100 citations.

Relevant References:
Physical Review D90 (2014) 094503
Physical Review Letters 113 (2014) 082001
Physical Review D86 (2012) 034509
Physical Review D86 (2012) 094503
Physical Review D85 (2012) 054503

 

Dark Matter and LHC Physics

Graesser is revisiting the topological dark matter scenario and generalizing it in several directions. He is collaborating with J. Osinski, a University of New Mexico graduate student visiting Los Alamos for 6 months on a DOE Office of Science Graduate Student Research Award. They are exploring how the predictions for the relic dark matter density in such a scenario depends on the cosmological history prior to Big Bang Nucleosynthesis. A draft is in preparation for posting to the arXiv.

He is also continuing his work with Tuhin Roy (TATA) and Arun Thalapillil (Pune) on improving the sensitivity of the LHC to new TeV-scale physics scenarios.

Relevant References:
Physics Letters B749 (2014) 293
arXiv:1311.2028
Physical Review Letters111 (2013) 121802
JHEP 1302(2013) 046
JHEP 1210(2012) 025
Physics Letters B714 (2012) 267
Physics Review D85 (2012) 054512
arXiv:1107.2666
JHEP 1110(2011) 110

 

Neutrinoless double beta decay

During this quarter Graesser has been revisiting the contribution of Majorana neutrinos to the neutrinoless double beta decay process, using chiral effective field theory. He and collaborators (Cirigliano, Dekens, de Vries, Mereghetti, Pastore, van Kolck) posted a preprint ``A new leading contribution to neutrinoless double beta decay”, arXiv:1802.10097, which has been accepted for publication in Physical Review Letters. In this paper, the authors identify a new contact operator involving 4 nucleons - i.e., short range - which occurs at the same order as the neutrino potential induced by Majorana neutrinos. The evidence is based on renormalization and using chiral symmetry to relate this process to other isospin breaking observables involving two nucleons. This effect had been missed in all previous computations. The authors speculate on the impact this new contribution will have on nuclear matrix elements of relevance to experimental searches.

Graesser and collaborators (Cirigliano, Dekens, de Vries, Mereghetti) have developed a "master decay" formula that computes the neutrinoless double decay process induced by Majorana neutrinos, as well as any other Beyond the Standard Model physics described at low energies by dimension-7 and/or dimension-9 Delta L=2 violating operators. This master formula is derived using chiral effective field theory, and includes all leading order effects. This formula supersedes all previous formulae for NDBD 0+ -> 0+ transitions, as it includes a rigorous derivation of all leading order chiral dynamics (leading order perturbative and non-perturbative renormalization effects), all relevant low-energy constants (known and unknown), a larger set of gauge invariant operators, and includes all possible interferences in the amplitude. It can be used to match to specific lepton number violating models, a point illustrated by matching the effective theory to the left-right symmetric model. A paper is in preparation.

Relevant References:
arXiv:1802.10097
Journal of High Energy Physics12 (2017) 82 arXiv:1708.09390
Journal of High Energy Physics (2017)99
Physics Letters B769 (2017) 460

 

MeV Axions and New Physics at the GeV Scale

Daniele S. M. Alves has worked on the following topics: (1) phenomenology of the QCD axion in the MeV mass range, and associated new physics at the GeV scale; (2) phenomenology of sterile neutrinos with BSM interactions, including a "sterile neutrino MSW effect", and associated implications for short baseline anomalies; and (3) generalizations of Tensor Networks and Entanglement Renormalization methods to continuous field theories. A proposal responding to the DOE call "Quantum Information Science Enabled Discovery For High Energy Physics" was developed and submitted.

Relevant References:
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 charges gA, gS and gT from the 2+1+1-flavor clover-on-HISQ calculations was completed, including the analysis of the very time consuming second physical mass HISQ ensemble with lattice size 963 ×192 at 0.06 fm on cluster and GPU computers at Los Alamos, at OLCF and using ERCAP allocations at NERSC. A paper describing the results was prepared and submitted for publication to PRD. The final analysis of flavor diagonal axial and tensor charges was completed. A paper describing the contribution of quark spin to the proton spin was prepared and submitted for publication to PRL. 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 completed and manuscripts describing the results were worked on. Results will be presented by Rajan Gupta and Yong-Chull Jang at Lattice 2018.

Relevant References:
arXiv:1806.09006
arXiv:1806.10604
Physical Review D96 (2017) 114503 arXiv:1705.06834
Physical Review D95:5 (2017) 074508
Physical Review D94:5 (2016) 054508
Physical Review D93:11 (2016) 114506
arXiv:1601.01730
Physical Review D92:9 (2015) 094511
Physical Review D89:9 (2014) 094502
Physical Review D85:5 (2012) 054512

 

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 operator were initiated. Analysis of data generated so far was carried out and results will be presented at Lattice 2018 by Tanmoy Bhattacharya.

Relevant References:
arXiv:1712.08557
arXiv:1701.04132
arXiv:1612.08438
arXiv:1601.02264
Physical Review D92:9 (2015) 114026
Physical Review Letters 112:21 (2015) 212002
arXiv:1502.07325
arXiv:1403.2445
arXiv:1212.4918

 

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 nucleon sigma term and the strangeness content of the proton, and the interaction of dark matter with nucleons. These matrix elements get contributions from disconnected diagrams that are computationally challenging to compute with high precision. Bhattacharya, Gupta and Yoon worked on two manuscript describing the results of extensive simulations carried out over the last three years for publication. They have analyzed the chiral and continuum extrapolation for the contribution of the flavor diagonal charges for the first time. A paper describing the contribution of quark spin to the proton spin was prepared and submitted for publication to PRL. They are continuing to collaborate with Gambhir, Orginos and Stathopoulos at William and Mary to develop a new method based on deflation and hierarchical probing to speed up the calculation of disconnected diagrams.

Relevant References:
arXiv:1806.10604
arXiv:1611.01193

 

Transverse Momentum Distribution Functions

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

Relevant References:
Physical Review D96 (2017) 094508 arXiv:1706.03406
arXiv:1611.01193
arXiv:1601.05717

 

Behavior of QCD at finite temperature

Investigated the properties of QCD at finite temperature, including the nature of the transition, the equation of state and the fluctuations of conserved charges (electric charge, strangeness, baryon number) around the transition temperature (140–160 MeV) as part of the HOTQCD collaboration during the period 2007-2015. The six resulting publications have over 2500 citations.

Relevant References:
Physical Review D90 (2014) 094503
Physical Review Letters 113 (2014) 082001
Physical Review D86 (2012) 034509
Physical Review D86 (2012) 094503
Physical Review D85 (2012) 054503
Physical Review D80 (2009) 014504

 

Dark Matter and LHC Physics

Graesser is continuing to work on topological dark matter scenario and generalizing it in several directions. He is collaborating with J. Osinski, a University of New Mexico graduate student visiting Los Alamos for 6 months on a DOE Office of Science Graduate Student Research Award. They are exploring how the predictions for the relic dark matter density in such a scenario depends on the cosmological history prior to Big Bang Nucleosynthesis. A draft is in preparation for posting to the arXiv.

He is also continuing his work with Tuhin Roy (TATA) and Arun Thalapillil (Pune) on improving the sensitivity of the LHC to new TeV-scale physics scenarios.

Relevant References:
Physics Letters B749 (2014) 293
arXiv:1311.2028
Physical Review Letters111 (2013) 121802
JHEP 1302(2013) 046
JHEP 1210(2012) 025
Physics Letters B714 (2012) 267
Physics Review D85 (2012) 054512
arXiv:1107.2666
JHEP 1110(2011) 110

 

Michael Graesser: Neutrinoless double beta decay

Graesser, in collaboration with V. Cirigliano, W. Dekens, J. de Vries, and E. Mereghetti, developed an effective field theory for lepton number violation (LNV) by 2 units, covering the large class of theories in which LNV mediators lie above the GeV scale. The new master formula for 0νββ decay supersedes all previous “master formulas” since it uses a minimal basis of operators and correct QCD RG equations; performs careful and systematic matching of quark operators onto the chiral theory of pions and nucleons; identifies all the needed LECs and includes their values where they are known; includes the leading effect dimension-5, dimension-7, and dimension-9 operators — including their interference terms — and includes non-perturbative renormalization of contact operators, a feature completely missed by all previous analyses. The team applied their master formula to obtain constraints on single LNV operators, and a number of benchmark points for the left-right symmetric model. For instance, in a particular bench mark set of mass parameters (mWR ~ 4.5 TeV, mνRi=1,2,3 ~ 10 GeV) – consistent with current LHC limits – they found that the induced dim-9 operators dominate over the active Majorana neutrino mass contributions and that this benchmark point is excluded by existing 0νββ decay limits, demonstrating the complementarily between LHC searches for LNV and neutrinoless double beta decay experiments. This work appeared as arXiv:1806.02780 and was submitted to JHEP.

Relevant References:
arXiv:1806.02780
arXiv:1802.10097
Journal of High Energy Physics12 (2017) 82 arXiv:1708.09390
Journal of High Energy Physics (2017)99
Physics Letters B769 (2017) 460

 

Daniel S. M. Alves

Daniele S. M. Alves has work in progress on: (i) Peccei-Quinn dynamics at the GeV scale; (ii) sterile neutrinos with Beyond the Standard Model interactions with quarks and leptons via light dark sector mediators; (iii) entanglement renormalization in effective field theories. Her paper on "A viable QCD axion in the MeV mass range" has been published in JHEP 1807 (2018) 092.

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 charges gA, gS and gT from the 2+1+1-flavor clover-on-HISQ calculations was completed and a paper describing the results was prepared and published in PRD. The final analysis of flavor diagonal axial and tensor charges was completed. A paper describing the contribution of quark spin to the proton spin was prepared and submitted for publication. A second paper describing the calculation of the flavor diagonal tensor charges was completed and submitted for publication. 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. Results were presented by Rajan Gupta and Yong-Chull Jang at Lattice 2018.

Relevant References:
arXiv:1808.07597
arXiv:1806.10604
Physical Review D98 (2018) 034503 arXiv:1806.09006
arXiv:1806.10604
Physical Review D96 (2017) 114503 arXiv:1705.06834
Physical Review D95:5 (2017) 074508
Physical Review D94:5 (2016) 054508
Physical Review D93:11 (2016) 114506
arXiv:1601.01730
Physical Review D92:9 (2015) 094511
Physical Review D89:9 (2014) 094502
Physical Review D85:5 (2012) 054512

 

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 operator are continuing. Analysis of data generated so far was carried out and results presented at Lattice 2018 by Tanmoy Bhattacharya.

Relevant References:
arXiv:1712.08557
arXiv:1701.04132
arXiv:1612.08438
arXiv:1601.02264
Physical Review D92:9 (2015) 114026
Physical Review Letters 112:21 (2015) 212002
arXiv:1502.07325
arXiv:1403.2445
arXiv:1212.4918

 

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 submitted two manuscript describing the results of extensive simulations carried out over the last three years for publication. These analyses included chiral and continuum extrapolation for the disconnected contribution of the flavor diagonal charges for the first time.

Relevant References:
arXiv:1808.07597
arXiv:1806.10604
arXiv:1611.01193

 

Transverse Momentum Distribution Functions

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

Relevant References:
Physical Review D96 (2017) 094508 arXiv:1706.03406
arXiv:1611.01193
arXiv:1601.05717

 

Dark Matter and LHC Physics

Graesser and University of New Mexico 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.

Relevant References:
Physics Letters B749 (2014) 293
arXiv:1311.2028
Physical Review Letters111 (2013) 121802
JHEP 1302(2013) 046
JHEP 1210(2012) 025
Physics Letters B714 (2012) 267
Physics Review D85 (2012) 054512
arXiv:1107.2666
JHEP 1110(2011) 110

 

Michael Graesser: Neutrinoless double beta decay

Graesser, in collaboration with V. Cirigliano, W. Dekens, J. de Vries, and E. Mereghetti, developed an effective field theory for lepton number violation (LNV) by 2 units, covering the large class of theories in which LNV mediators lie above the GeV scale. The new master formula for 0νββ decay supersedes all previous “master formulas” since it uses a minimal basis of operators and correct QCD RG equations; performs careful and systematic matching of quark operators onto the chiral theory of pions and nucleons; identifies all the needed LECs and includes their values where they are known; includes the leading effect dimension-5, dimension-7, and dimension-9 operators — including their interference terms — and includes non-perturbative renormalization of contact operators, a feature completely missed by all previous analyses. The team applied their master formula to obtain constraints on single LNV operators, and a number of benchmark points for the left-right symmetric model. For instance, in a particular bench mark set of mass parameters (mWR ~ 4.5 TeV, mνRi=1,2,3 ~ 10 GeV) – consistent with current LHC limits – they found that the induced dim-9 operators dominate over the active Majorana neutrino mass contributions and that this benchmark point is excluded by existing 0νββ decay limits, demonstrating the complementarily between LHC searches for LNV and neutrinoless double beta decay experiments. This work appeared as arXiv:1806.02780 and was submitted to JHEP.

Relevant References:
arXiv:1806.02780
Physical Review Letters 120:20 (2018) 202001 arXiv:1802.10097
Journal of High Energy Physics12 (2017) 82 arXiv:1708.09390
Journal of High Energy Physics (2017)99
Physics Letters B769 (2017) 460

 

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