Decay of Z into Three Pseudoscalar Bosons

We consider the decay of the $Z$ boson into three pseudoscalar bosons in a general two-Higgs-doublet model. Assuming $m_A$ to be very small, and that of the two physical neutral scalar bosons $h_1$ and $h_2$, $A$ only couples to $Z$ through $h_1$, we find the $Z \to A A A$ branching fraction to be negligible for moderate values of $\tan \beta \equiv v_2/v_1$, if there is no $\lambda_5 (\Phi_1^\dagger \Phi_2)^2 + h.c.$ term in the Higgs potential; otherwise there is no absolute bound but very large quartic couplings (beyond the validity of perturbation theory) are needed for it to be observable.Comment: 8 pages including 1 fi

Lower Bound on the Pseudoscalar Mass in the Minimal Supersymmetric Standard Model

In the Higgs sector of the Minimal Supersymmetric Standard Model, the mass of the pseudoscalar $A$ is an independent parameter together with $\tan \beta \equiv v_2/v_1$. If $m_A$ is small, then the process $e^+ e^- \to h + A$ is kinematically allowed and is suppressed only if $\tan \beta$ is small. On the other hand, the mass of the charged Higgs boson is now near $M_W$, and the decay $t \to b + h^+$ is enhanced if $\tan \beta$ is small. Since the former has not been observed, and the branching fraction of $t \to b + W$ cannot be too small (by comparing the experimentally derived $t \bar t$ cross section from the leptonic channels with the theoretical prediction), we can infer a phenomenological lower bound on $m_A$ of at least 60 GeV for all values of $\tan \beta$.Comment: 11 pages including 2 figs, reference adde

Higgs and Z-boson Signatures of Supersymmetry

In supersymmetric theories of nature the Higgsino fermionic superpartner of the Higgs boson can arise as the lightest standard model superpartner depending on the couplings between the Higgs and supersymmetry breaking sectors. In this letter the production and decay of Higgsino pairs to the Goldstone fermion of supersymmetry breaking and the Higgs boson, h, or gauge bosons, Z or $\gamma$ are considered. Relatively clean di-boson final states, hh, $h \gamma$, hZ, $Z \gamma$, or ZZ, with a large amount of missing energy result. The latter channels provide novel discovery modes for supersymmetry at high energy colliders since events with Z bosons are generally rejected in supersymmetry searches. In addition, final states with real Higgs bosons can potentially provide efficient channels to discover and study a Higgs signal at the Fermilab Tevatron Run II.Comment: 11 pages, LaTeX, 3 figure

Unleasing Z Monster

Houston Community College will share experiences of creating what sometimes feels like an enormous and unrealizable task and what may seem to be a monstrous educational disruption, a Z-Degree. Building a Z-Degree might seem like simply a matter of packaging courses, but in reality, it requires design, intention, and cultivation. After years of piecemeal attempts to adopt and promote OER, HCC gained focus with a directive to launch a Z-Degree, which came from multiple stakeholders, including students, Board of Trustees, senior administration, and faculty champions. This commitment enabled us to secure external and internal funding sources, clarify policies and procedures, and ultimately place OER on a solid foundation for the future. We will share our process for revising and adopting an OER policy guide, identifying and recruiting faculty, and engaging with multiple stakeholders within the institution (Board of Trustees, administration, faculty, libraries, CTLE, and students). HCC has partnered with Lumen Learning to provide initial training and course hosting, and we are working with our Institute for Instructional Engagement & Development to create a sustainable infrastructure to build our capacity of OER course offerings. In some cases, it has been necessary to make compromises to bring critical programs on board, but the college has done so out of a commitment to the ultimate goal of building a complete degree plan and developing OERs options for the future. Finally, HCC is establishing a program for data collection and analysis in order to understand the effects of the initiative on key indicators. This session will include real time polls and Twitter feeds. It is aimed at all levels, but particularly colleges who want to launch a Z Degree