Emerging treatment options for the management of brain metastases in patients with HER2-positive metastatic breast cancer.

The widespread use of trastuzumab in the past decade has led to a significant and measureable improvement in the survival of patients with human epidermal growth factor receptor-2 (HER2) overexpressing breast cancer, and in many ways has redefined the natural history of this aggressive breast cancer subtype. Historically, survival in patients with HER2-positive disease was dictated by the systemic disease course, and what appears to be the central nervous system (CNS) tropism associated with HER2-amplified tumors was not clinically evident. With improved systemic control and prolonged survival, the incidence of brain metastases has increased, and CNS disease, often in the setting of well-controlled extracranial disease, is proving to be an increasingly important and clinically challenging cause of morbidity and mortality in patients with HER2-positive advanced breast cancer. This review summarizes the known clinical data for the systemic treatment of HER2-positive CNS metastases and includes information about ongoing clinical trials of novel therapies as well as emerging strategies for early detection and prevention

Complementarity of LHC and EDMs for Exploring Higgs CP Violation

We analyze the constraints on a CP-violating, flavor conserving, two Higgs doublet model from the measurements of Higgs properties and from the search for heavy Higgs bosons at LHC, and show that the stronger limits typically come from the heavy Higgs search channels. The limits on CP violation arising from the Higgs sector measurements are complementary to those from EDM measurements. Combining all current constraints from low energy to colliders, we set generic upper bounds on the CP violating angle which parametrizes the CP odd component in the 126 GeV Higgs boson.Comment: 34 pages, 17 figures, 2 tables; references added, constraints from Higgs decay into tau updated, version accepted for publication in JHE

Electroweak Effective Operators and Higgs Physics

We derive bounds from oblique parameters on the dimension-6 operators of an effective field theory of electroweak gauge bosons and the Higgs doublet. The loop- induced contributions to the S, T, and U oblique parameters are sensitive to these contributions and we pay particular attention to the role of renormalization when computing loop corrections in the effective theory. Limits on the coefficients of the effective theory from loop contributions to oblique parameters yield complementary information to direct Higgs production measurements.Comment: 33 pages, 6 figures; additional scalar operator included and references adde

Higgs CP Violation from Vectorlike Quarks

We explore CP violating aspects in the Higgs sector of models where new vectorlike quarks carry Yukawa couplings mainly to the third generation quarks of the Standard Model. We point out that in the simplest model, Higgs CP violating interactions only exist in the hWW channel. At low energy, we find that rare B decays can place similarly strong constraints as those from electric dipole moments on the source of CP violation. These observations offer a new handle to discriminate from other Higgs CP violating scenarios such as scalar sector extensions of the Standard Model, and imply an interesting future interplay among limits from different experiments.Comment: 19 pages, 5 figure

Exploring Resonant di-Higgs production in the Higgs Singlet Model

We study the enhancement of the di-Higgs production cross section resulting from the resonant decay of a heavy Higgs boson at hadron colliders in a model with a Higgs singlet. This enhancement of the double Higgs production rate is crucial in understanding the structure of the scalar potential and we determine the maximum allowed enhancement such that the electroweak minimum is a global minimum. The di-Higgs production enhancement can be as large as a factor of ~ 18 (13) for the mass of the heavy Higgs around 270 (420) GeV relative to the Standard Model rate at 14 TeV for parameters corresponding to a global electroweak minimum.Comment: 25 pages, 14 figures. Version approved for publication. Discussion of Z2 symmetric limit improved and references adde

Top Partners and Higgs Boson Production

The Higgs boson is produced at the LHC through gluon fusion at roughly the Standard Model rate. New colored fermions, which can contribute to $gg\rightarrow h$, must have vector-like interactions in order not to be in conflict with the experimentally measured rate. We examine the size of the corrections to single and double Higgs production from heavy vector-like fermions in $SU(2)_L$ singlets and doublets and search for regions of parameter space where double Higgs production is enhanced relative to the Standard Model prediction. We compare production rates and distributions for double Higgs production from gluon fusion using an exact calculation, the low energy theorem (LET), where the top quark and the heavy vector-like fermions are taken to be infinitely massive, and an effective theory (EFT) where top mass effects are included exactly and the effects of the heavy fermions are included to ${\cal O}(1/M^2_X)$. Unlike the LET, the EFT gives an extremely accurate description of the kinematic distributions for double Higgs production.Comment: 37 pages, 11 figures. Minor changes to Figs. 8-1

Zero bias conductance peak in Majorana wires made of semiconductor-superconductor hybrid structures

Motivated by a recent experimental report[1] claiming the likely observation of the Majorana mode in a semiconductor-superconductor hybrid structure[2,3,4,5], we study theoretically the dependence of the zero bias conductance peak associated with the zero-energy Majorana mode in the topological superconducting phase as a function of temperature, tunnel barrier potential, and a magnetic field tilted from the direction of the wire for realistic wires of finite lengths. We find that higher temperatures and tunnel barriers as well as a large magnetic field in the direction transverse to the wire length could very strongly suppress the zero-bias conductance peak as observed in Ref.[1]. We also show that a strong magnetic field along the wire could eventually lead to the splitting of the zero bias peak into a doublet with the doublet energy splitting oscillating as a function of increasing magnetic field. Our results based on the standard theory of topological superconductivity in a semiconductor hybrid structure in the presence of proximity-induced superconductivity, spin-orbit coupling, and Zeeman splitting show that the recently reported experimental data are generally consistent with the existing theory that led to the predictions for the existence of the Majorana modes in the semiconductor hybrid structures in spite of some apparent anomalies in the experimental observations at first sight. We also make several concrete new predictions for future observations regarding Majorana splitting in finite wires used in the experiments.Comment: 5 pages, 6 figures: revised submitted versio