3: the mu term in the MSSM superpotential gives mass to the higgsinos. The EWSB conditions require that mu be of the order of the soft masses and of the order of the weak scale; 4: mu problem: if mu is a parameter of the SUSY theory valid up to M_planck, why is it not of O(M_planck) itself? Giudice-Masiero solution: mu is generated together by the soft terms by the mechanism of SUSY breaking; NMSSM solution: mu arises at the weak scale as the vev of an additional singlet. 5-8: Higgs sector of the NMSSM: the scalar, pseudoscalar and fermionic components of the singlet superfield mix with the corresponding components of the MSSM-like doublet superfields. In the pseudoscalar sector, only P1 and P2 contribute to the Goldstone boson, but all three pseudoscalar components contribute to the two physical pseudoscalars A1 and A2. 9-10: in the limit in which the singlet vev is much larger than the weak scale the singlet decouples from the MSSM-like Higgs sector; however, the mass of the lightest MSSM-like Higgs retains an additional, F-term induced contribution proportional to lambda^2*sin(2Beta)^2. 11: through the effect of the additional quartic coupling, for large lambda the lightest Higgs boson mass is maximized at low tanB (in contrast with the case of the MSSM in which the mass is maximized at large tanB). 12: another interesting feature of the NMSSM is the possibility that a 100-GeV Scalar is not excluded by the LEP. This can happen if a sizeable singlet component suppresses the coupling to the Z, or if the scalar decays mostly into two pseudoscalars which are in turn too light to decay into b quarks. This scenario would also allow for lighter squarks than is typical in the MSSM. 14-16: list of the calculations of the MSSM Higgs masses, from the early calculations of 1991 to the three-loop results of last year. Most public computer codes implement a full one-loop calculation (a la PBMZ, or variations) and some linear combination of the zero-momentum results of Slavich et al. and Heinemeyer et al. for the two-loop quark/squark contributions. 17: the situation of the NMSSM is not quite as advanced. The one-loop quark/squark contributions have been computed in the effective potential approach; the one-loop gauge/gaugino and Higgs/higgsino contributions, as well as the two-loop quark/squark contributions, have been computed only at the leading-logarithmic level in the renormalization group approach. All of these results are implemented in the public computer code NMHDECAY. 18-20: the situation of the NMSSM is comparable to the situation of the MSSM as it was in the mid nineties. 21: my paper with G. Degrassi, arXiv:0907.4682, provides a complete one-loop calculation of the neutral Higgs masses (PBMZ-like) and an effective potential calculation of the two-loop strong corrections. 22: summary of the one-loop calculation. We need to compute self-energies and tadpole diagrams for the CP-even Higgses, plus the self-energies of the CP-odd Higgses and of the gauge bosons. 23: summary of the two-loop calculation in the effective potential approach: we need to compute the two-loop vacuum diagrams in terms of field-dependent parameters and take the first and second derivatives with respect to the fields. 24: the parameters in the top/stop sector depend on the Higgs fields through the left-right mixing terms of the top and stop mass matrices. Our set of field-dependent parameters includes the top and stop squared masses, the stop mixing angle and a combination of the phases of the left-right mixing terms. 25: compact formulae for the corrections to the CP-even mass matrix. The first three lines correspond to the known MSSM results while the last three are specific to the NMSSM. 26: definitions of the functions appearing in slide 25, in terms of the derivatives of the effective potential w.r.t. the field-dependent parameters. The derivatives are computed at the minimum of the potential. 27-28: excerpt from arXiv:0907.4682, showing that the full two-loop formulae for the derivatives fit in a four-page appendix. 30-32: effect of the one-loop corrections to the two lightest scalar masses as a function of lambda, for a specific choice of the remaining parameters. The comparison between the dotted and dashed lines shows that the bulk of the correction to the lightest scalar mass comes from the quark/squark contribution, as in the MSSM. However, the comparison between the dashed and solid lines shows that the remaining electroweak and higgs/higgsino contributions can amount to several GeV for both masses. 33: effect of the one-loop corrections on the mixing between singlet and doublets in the two lightest scalars. The plot shows the square of the (i,3) element of the scalar mixing matrix a function of lambda. For small lambda the lightest scalar is mostly doublet and the other is mostly singlet, but when lambda increases they cross over. The value of lambda for which they cross over depends crucially on the accuracy of the calculation. 34: effect of the one-loop corrections to the lightest pseudocalar mass as a function of lambda. In this scenario the lightest pseudoscalar is mostly singlino thus it is not affected by the quark/squark contributions. However, the higgs/higgsino contributions can still amount to a few GeV. 35-39: effect of the two-loop corrections to the two lightest scalar masses as a function of a common squark mass MS, for a specific choice of the remaining parameters. The comparison between the dotted, dashed and solid lines shows that the leading-logarithmic terms account only for a fraction of the total two-loop corrections to the lightest scalar mass, especially for small MS. 40: same plot as above with the opposite value of At. It shows that the very good agreement in the previous slide between the leading-logarithmic and "full" two-loop results for the mass of the second-lightest scalar was due to an accidental cancellation. 41: effect of the two-loop corrections on the mixing between singlet and doublets in the two lightest scalars. Smaller than the effect of the one-loop corrections but still visible. 43: conclusions: the newly computed corrections are necessary for a meaningful comparison between the MSSM and NMSSM predictions for the Higgs sector. 45: to-do list: implement the new results into NMHDECAY; extend the calculation to the charged Higgs; compute the two-loop corrections controlled only by the Yukawa couplings.