The recent availability of a consistent electron collision cross-section set for the ultra-low GWP HFO-1234ze(E) (HFO) enables performance simulations of resistive plate chambers (RPCs) operated with HFO-based gas mixtures. We present a simulation framework that reproduces key detector observables measured in trigger-purpose RPCs, such as detection efficiency and cluster size. The simulation additionally provides new insights into streamer formation through a novel streamer inception criterion that captures the observed trends in streamer probability. For mixtures containing CO2, HFO, SF6, and isobutane, the Pareto front between avalanche-streamer separation and relative CO2 equivalent emissions is evaluated using a multi-objective Bayesian optimization approach under a low working point constraint, so the mixture can be used with already installed infrastructure. The optimization confirms that the ECO2 gas mixture (60% CO2, 35% HFO, 4% isobutane, 1% SF6), previously identified through experimental studies, is a Pareto optimal choice when the operation is constrained to a low working point. If higher working points are acceptable, mixtures with a higher HFO percentage provide larger avalanche-streamer separation while enabling a reduction of the SF6 percentage, thereby reducing the environmental impact even further.
We recall our work in the 1980s taking seriously the maximal eleven dimensions of supergravity, in particular the round, left squashed and right squashed S^7 compactifications to D=4 yielding 𝒩=8, 𝒩=1 and 𝒩=0, respectively. This involved Kaluza-Kein techniques that have found wider applications such as spontaneous compactification, holonomy and supersymmetry, topology versus geometry, squashing and Higgs, vacuum stability and consistent truncations.
The U-dualities of maximally supersymmetric nonchiral supergravity (SUGRA) theories lead to strong constraints on the nonperturbative structure of quantum gravity. In this paper, we determine spin- and pinlifts of these dualities, which extend this action to fermionic degrees of freedom. Among other things, this allows us to access nonsupersymmetric sectors of these low energy effective field theories in which bosonic and fermionic degrees of freedom are treated differently. We use this refinement of the duality groups, in tandem with the Swampland cobordism conjecture, to predict new codimension-two branes. These are a natural generalization of the recently discovered R7-branes of type II string theories. The first bordism groups for Spin-twisted duality bundles that follow directly from the Abelianization of the duality groups. Viewing the SUGRA theory as the low energy limit of a toroidal compactification of M-theory, winding around these codimension-two defects enacts a reflection around one of the torus directions, which, in the effective field theory, appears as a charge conjugation symmetry. We establish some basic properties of such branes, including determining Bogomol'nyi-Prasad-Sommerfield objects which can end on it, as well as braiding rules and bound states realized by multiple reflection branes.
We carry out an Effective Field Theory (EFT) study of the pp ->(t) over bar tZh process in the final state. This process can uniquely probe the (t) over bar tZh couplings arising from higher dimensional EFT operators and can also provide bounds on (t) over bar tZ coupling deviations. We highlight the importance of the proposed proton-proton Future Circular Collider (FCC-hh) to study this process and then perform a complete collider analysis by examining the relevant background processes. This allows us to determine the FCC-hh sensitivity to probe anomalous (t) over bar tZh couplings.
The recently proposed swampland cobordism conjecture predicts the existence of new nonsupersymmetric objects which supplement the spectrum of low-energy gravitational effective field theories. In this paper, we study a subset of these defects related to the Gliozzi-Scherk-Olive projection on the string worldsheet. These include the predicted domain wall between type IIA and IIB superstring theories and the newly discovered R7-brane. We study these defects in two different ways: via long-string probes and targetspace effective field theory. We find that the R7-brane can be identified with a collapsed cylindrical configuration of the IIA/IIB wall, and further, that the R7-brane is stable, in contrast to previous expectations. Moreover, we argue that BPS D-branes pulled across the IIA/IIB wall become non-BPS D-branes, which we identify with fluxbrane configurations. We show that the non-BPS D-branes of either type II theory are charged under a Z2 remnant of the Ramond-Ramond potentials of the other, which we identify with the mod 2 reduction of the Ramond-Ramond fluxes. Similar considerations provide a complementary perspective on the heterotic so(32) S-duals of known non-BPS 7- and 8-branes in type I string theory.
