Widom–Larsen theory

The Widom–Larsen theory is a proposed explanation for supposed Low Energy Nuclear Reactions (LENR) developed in 2005 by Allan Widom and Lewis Larsen. In the paper describing the idea, they claim that ultra low momentum neutrons are produced in the cold fusion apparatuses{{Cite web |url=http://discovermagazine.com/2012/nov/27-big-idea-bring-back-the-cold-fusion-dream |title=Big Idea: Bring Back the "Cold Fusion" Dream. A new theory may explain the notorious cold fusion experiment from two decades ago, reigniting hopes of a clean-energy breakthrough. |last=Anderson |first=Mark |location=Discover Magazine |date=23 October 2012}} during weak interactions when protons capture "heavy" electrons from metallic hydride surfaces.{{Cite journal |last1=Widom |first1=A |last2=Larsen |first2=L |title=Ultra Low Momentum Neutron Catalyzed Nuclear Reactions on Metallic Hydride Surfaces |journal= The European Physical Journal C|volume=46 |issue=1 |pages=107–111 |date=April 2006 |doi=10.1140/epjc/s2006-02479-8 |arxiv=cond-mat/0505026 |bibcode=2006EPJC...46..107W |s2cid=55478462 }} One source has held that it is "unlikely the electron energy threshold for neutron production can be reached in a metal lattice

system without a substantial energy input".{{Cite journal |last=Tennfors |first=Einor |title=On the idea of low energy nuclear reactions in metallic lattices by producing neutrons from protons capturing "heavy" electrons |url=https://www.researchgate.net/publication/260246109 |journal= The European Physical Journal Plus|volume=128 |issue=2 |pages=15 |date=15 February 2015 |doi=10.1140/epjp/i2013-13015-3 |access-date=24 March 2017|bibcode=2013EPJP..128...15T |s2cid=55677855 }}

The idea was expanded by Yogendra Srivastava together with Widom and Larsen in 2014, who went on to propose that it could be an explanation for neutrons observed in exploding wire experiments, solar corona and flares, and neutron production in thunderstorms.{{Cite journal |last1=Srivastava |first1=Y |last2=Widom |first2=A |last3=Larsen |first3=L |title=A primer for electroweak induced low-energy nuclear reactions |url=http://www.ias.ac.in/describe/article/pram/075/04/0617-0637 |journal=Pramana |date=October 2014 |access-date=24 March 2017}} However, unrealistic concentrations of free electrons are needed for the neutron yield to be a significant component of thunderstorm neutrons, discounting the explanation.{{Cite journal |last1=Babich |first1=L P |last2=Bochkov |first2=E I |last3=Kutsyk |first3=I M |last4=Rassoul |first4=H K |title=Analysis of fundamental interactions capable of producing neutrons in thunderstorms |journal=Physical Review D |volume=89 |issue=9 |pages=093010 |date=13 May 2014 |doi=10.1103/PhysRevD.89.093010 |bibcode=2014PhRvD..89i3010B }}{{Cite journal |last=Babich |first=L P |title=Fundamental processes capable of accounting for the neutron flux enhancements in a thunderstorm atmosphere |journal=Journal of Experimental and Theoretical Physics |volume=118 |issue=3 |pages=375–383 |doi=10.1134/S1063776114030017 |bibcode=2014JETP..118..375B |year=2014 |s2cid=195218932 }}{{Cite journal |last=Babich |first=L P |title=Analysis of a laboratory experiment on neutron generation by discharges in the open atmosphere |journal=Physical Review C |volume=92 |issue=4 |pages=044602 |date=8 October 2015 |doi=10.1103/PhysRevC.92.044602 |bibcode=2015PhRvC..92d4602B }}