Properties of Discrete Black Hole Hair

We revisit the physical effects of discrete $\mathbb{Z}_p$ gauge charge on black hole thermodynamics, building on the seminal work of Coleman, Preskill, and Wilczek. Realising the discrete theory from the spontaneous breaking of an Abelian gauge theory, we consider the two limiting cases of interest, depending on whether the Compton wavelength of the massive vector is much smaller or much larger than the size of the black hole -- the so-called thin- and thick-string limits respectively. We find that the qualitative effect of discrete hair on the mass-temperature relationship is the same in both regimes, and similar to that of unbroken $U(1)$ charge: namely, a black hole carrying discrete gauge charge is always colder than its uncharged counterpart. In the thick-string limit, our conclusions bring into question some of the results of Coleman et al., as we discuss. Further, by considering the system to be enclosed within a finite cavity, we argue how the unbroken limit may be smoothly defined, and the unscreened electric field of the standard Reissner-Nordstrom solution recovered.Comment: 19 pages, 5 figures; references added, matches published versio

LHCb anomalies from a natural perspective

Tension between the Standard Model (SM) and data concerning $b \rightarrow s$ processes has become apparent. Most notoriously, concerning the $R_K$ ratio, which probes lepton non-universality in $b$ decays, and measurements involving the decays $B \rightarrow K^* \mu^+ \mu^-$ and $B_s \rightarrow \phi \mu^+ \mu^-$. Careful analysis of a wide range of $b \rightarrow s$ data shows that certain kinds of new physics can significantly ameliorate agreement with experiment. Here, we show that these $b \rightarrow s$ anomalies can be naturally accommodated in the context of Natural Scherk-Schwarz Theories of the Weak Scale -- a class of models designed to address the hierarchy problem. No extra states need to be introduced in order to accommodate these anomalies, and the assumptions required regarding flavor violating couplings are very mild. Moreover, the structure of the theory makes sharp predictions regarding $B$ meson decays into final states including $\tau^+ \tau^-$ pairs, which will provide a future test of these models.Comment: 14 pages plus appendices, 3 figures; references added, published in JHE

Data encoding efficiency in pixel detector readout with charge information

The average minimum number of bits needed for lossless readout of a pixel detector is calculated, in the regime of interest for particle physics where only a small fraction of pixels have a non-zero value per frame. This permits a systematic comparison of the readout efficiency of different encoding imple- mentations. The calculation is compared to the number of bits used by the FE-I4 pixel readout chip of the ATLAS experiment.Comment: 13 pages, 6 figure

Rescuing Massive Photons from the Swampland

Stringent Swampland conjectures aimed at effective theories containing massive abelian vectors have recently been proposed (arXiv:1808.09966), with striking phenomenological implications. In this article, we show how effective theories that parametrically violate the proposed conjectures can be UV-completed into theories that satisfy them. The UV-completion is accessible through both the St\"uckelberg and Higgs mechanisms, with all dimensionless parameters taking $\mathcal{O}(1)$ values from the UV perspective. These constructions feature an IR limit containing a light vector that is parametrically separated from any other massive states, and from any cut-off scale mandated by quantum gravity consistency requirements. Moreover, the cut-off--to--vector--mass ratio remains parametrically large even in the decoupling limit in which all other massive states (including any scalar excitations) become arbitrarily heavy. We discuss how apparently strong constraints imposed by the proposed conjectures on phenomenologically interesting models, including specific production mechanisms of dark photon dark matter, are thereby circumvented.Comment: 15 page

An infra-red finger tracking system used in the assessment and remediation of “graph-as-picture” misconceptions

The workshop presentation will describe a specialized ap- plication of Lee’s “Wiimote Whiteboard” [7] an infra-red camera based tracking system which uses the Nintendo Wii wireless remote control unit and Bluetooth. Young students wear a very small infra-red LED on their index finger with a forefinger/thumb operated micro-switch for produ- cing “mouse clicks”. This system is combined with a vertically mounted data projector or a horizontally mounted regular computer LCD display, creating a cost-effective large interactive touch surface. The system has a fast response time and has been used with primary school students in diagrammatic knowledge (graphicacy) assessment [4] and in interactive dynalinked diagrammatic applications [5]. These applications were de- signed to investigate the “graph-as-picture” misconception and they will be described and demonstrated at the workshop

Field Measurements of Spontaneous Potential (SP) for Smart Well Monitoring and Control. A Field Test in the UK Chalk Aquifer

Imperial Users onl