Here is the referee report that rejected my paper. From Rajamani Narayanan Senior Assistant to the Editor Physical Review D ------------------------------------------------------------------------------- This paper attempts to solve the cosmological constant problem using supersymmetry. The author does give a nice overview of supersymmetry and the cosmological constant problem in the first part of the paper, however none of this is new, and is therefore not appropriate for publication in Physical Review D. The solution that the author is presenting is a tantalizing possibility that particle physicists have been tought [sic; "have thought" was apparently meant] about a long time ago. The point that the author makes is that even in the presence of spontaneously broken supersymmetries the supertrace of the masses of the particles still vanishes, and this is exactly one of the quantities that appears in the one loop expression for the cosmological constant. This is all known for a long time, and unfortunately does not solve the cosmological constant problem. In fact, these sum rules were exactly the ones that hampered for a long time the development of a phenomenologically acceptable supersymmetric version of the standard model. The problem is, that at tree level, these sum rules hold representation by representation. So from this one can show, that if these sum rules really hold, then one should have already observed at least one superpartner, since the sum rule can hold only if some of the superpartners become lighter than the ordinary particles. A beautiful derivation of this result can be found in the famous paper by Dimopoulos and Georgi, Nucl.Phys.B193:150,1981. This is the reason why none of the early attempts by Fayet and others led to an acceptable supersymmetric standard model. So in order to be able to build such a model, one has to badly violate the sum rule in Eq. (16) of this paper. How is this possible, if we agreed that the tree level result is valid, and violated only by loop corrections? The way ALL realistic models of supersymmetry breaking achieve this is by assuming, that the breaking scale of supersymmetry is very high, but it happens in a sector very well separated from the standard model (hidden sector). In this sector, the supertrace formula (16) is very well satisfied. The standard model only learns about supersymmetry breaking by loop effects (either gravitational loops or gauge loops). Thus for the standard model fields and their superpartners, the loop corrections will be the LEADING contributions to their masses. And these are the masses that are supposed to be of order TeV (and as explained above, the masses of the hidden sector particles are much heavier, and the TeV scale comes out as a loop suppressed version of the real SUSY breaking scale). This way we see, that for the standard model particles the sum rule is not at all obeyed, and the resulting cosmological constant is of order TeV^4, which is still many orders of magnitude higher than the expected (10^-3 eV)^4. Therefore, a realistic supersymmetric model after susy breaking can not itself resolve the cosmological constant problem. For example, in one of the most popular recent models called gauge mediation of supersymmetry breaking one can explicitly check that the resulting correction to the supertrace formula is of order TeV^2. A nice reference for these models is G.F. Giudice, R. Rattazzi Phys.Rept.322:419-499,1999. However, I should add that there are several attempts along the lines that the author is suggesting to solve the cosmological constant and the hierarchy problems, that is by cancelling the supertraces in a theory WITHOUT requiring supersymmetry. The nicest description of these attempts can be found in the paper Keith R. Dienes hep-ph/0104274. In summary, I find that even though the paper is a nice attempt at solving the cosmological constant problem, since the concepts in the paper are not new, and since as explained above the mechanism the author is trying to argue for to solve the cosmological constant problem can not possibly work in a realistic supersymmetric model, I recommend not to publish this paper in Physical Review D. -------------------------------------------------------------------------