15,400 research outputs found
An alternative view on the electroweak interactions
We discuss an alternative to the Higgs mechanism which leads to gauge
invariant masses for the electroweak bosons. The key idea is to reformulate the
gauge invariance principle which, instead of being applied as usual at the
level of the action, is applied at the level of the quantum fields. In other
words, we define gauge invariant quantum fields which are used to build the
action. In that framework, the Higgs field is not necessarily a physical degree
of freedom but can merely be a dressing field that does not propagate. If the
Higgs boson is not propagating, the weak interactions must become strongly
coupled below 1 TeV and have a non-trivial fixed point and would thus be
renormalizable at the non-perturbative level. On the other hand, if a gauge
invariant Higgs boson is introduced in the model, its couplings to the fermions
and the electroweak bosons can be quite different from those expected in the
standard model.Comment: 10 page
On the Energetics of the HCO + C CH + CO Reaction and Some Astrochemical Implications
We explore the energetics of the titular reaction, which current
astrochemical databases consider open at typical dense molecular (i.e., dark)
cloud conditions. As is common for reactions involving the transfer of light
particles, we assume that there are no intersystem crossings of the potential
energy surfaces involved. In the absence of any such crossings, we find that
this reaction is endoergic and will be suppressed at dark cloud temperatures.
Updating accordingly a generic astrochemical model for dark clouds changes the
predicted gas-phase abundances of 224 species by greater than a factor of 2. Of
these species, 43 have been observed in the interstellar medium. Our findings
demonstrate the astrochemical importance of determining the role of intersystem
crossings, if any, in the titular reaction.Comment: Accepted for publication in ApJ; 14 pages, 2 figures, and 1 tabl
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