Particle theory

Abstract:

Abstract:

We calculate the next-to-next-to-next-to-leading order (N$^3$LO) QCD corrections to vector-boson fusion (VBF) Higgs pair production in the limit in which there is no partonic exchange between the two protons. We show that the inclusive cross section receives negligible corrections at this order, while the scale variation uncertainties are reduced by a factor four. We present differential distributions for the transverse momentum and rapidity of the final state Higgs bosons, and show that there is almost no kinematic dependence to the third order corrections. Finally we study the impact of deviations from the Standard Model in the trilinear Higgs coupling, and show that the structure of the higher order corrections does not depend on the self-coupling. These results are implemented in the latest release of the proVBFH-incl program.

Abstract:

Particle physics is sometimes described as going through a crisis, notably because of the continued lack of discovery of physics beyond the Standard Model, despite the LHC having operated at close to maximal energy for some years now. Here, I argue that we should not underestimate the significance of recent progress and future prospects in the Higgs sector of the Standard Model. This is especially the case for the Yukawa interactions and the structure of the Higgs potential, both of which are unlike any sector that has been established and stress-tested before in particle physics. Other topics that I touch on include the still substantial scope for increasing the reach of searches at LHC, the increasing role of precision in hadron-collider physics and the rich interplay that is developing between heavy-ion and proton-proton physics.

Abstract:

We study F-theory duals of heterotic line bundle models on elliptically fibered Calabi-Yau threefolds. These models necessarily contain NS5-branes which are geometrized in the dual F-theory compactifications. We initiate a systematic study of the correspondence between various configurations of NS5-branes and the dual geometries in F-theory and perform several checks of the duality. Furthermore, we discuss the singular transitions between different configurations of NS5-branes.