The LENR hypothesis is that:
(1) there is some way to increase nuclear reaction cross-sections enormously (10s of OOM) above what is expected at a given energy.
(2) coupled with this there is some way in which the normal high energy nuclear reaction products are turned (almost all) into thousands of much lower energy particles.
As you'll no doubt appreciate, there's not one LENR conjecture, as LENR is a catch-all that encompasses a range of odd experimental anomalies, for which a unifying principle is elusive. Under this umbrella there are certain families of observations. For example there's the so-called "Fleischmann and Pons heat effect," which is something like this:
- In a Fleischmann and Pons electrolytic cell with a palladium cathode and D2O,
- sometimes excess heat is reported significantly above what could be explained by chemical reactions,
- and excess heat has been correlated with helium.
If it is true that helium is created in the Fleischmann and Pons heat effect, there must be a nuclear mechanism of some kind, in contrast to a chemical or supra-chemical one. What mechanism is proposed may not be recognizable to people familiar with so-called "hot fusion" processes. Clearly people will differ on how seriously they take the reports on the Fleischmann and Pons heat effect. I personally take them seriously.
There are other anomalies, which might or might not overlap with the Fleischmann and Pons heat effect (which is in PdD), such as the "anomalous heat effect," which just looks at excess heat and doesn't specify the material or type of system. And there are a number of kinds of LENR experiments where the focus is on observations that are hard to explain in terms other than nuclear ones, such as small amounts of neutrons, transmutations, and so on, but don't necessarily involve anomalous heat.
Only in the context of a specific LENR theory or family of theories would we find the suggestions that "there is some way to increase nuclear reaction cross-sections enormously (10s of OOM) above what is expected at a given energy" and "this there is some way in which the normal high energy nuclear reaction products are turned (almost all) into thousands of much lower energy particles." Admittedly, these things might often be suggested, but as suggestions they are not universal or even possibly predominant. There are, for example, the so-called "deep Dirac level" family of theories which suggest that electrons can relax to orbitals below the ground state, giving off significant energy in the process. This family of LENR conjectures might be considered a supra-chemical one, and they address themselves almost solely to the anomalous heat effect.
My own preferred lead for understanding some LENR experiments, for example, involving induced alpha and beta decay and fission, along with electron capture, says nothing about cross sections or fractionating a result across thousands of particles (except indirectly, through stopping).