Planar radiation zeros in five-parton QCD amplitudes

We demonstrate the existence of `planar', or `type-II', radiation zeros in 5-parton QCD scattering processes. That is, the Born amplitudes are shown to completely vanish for particular kinematic configurations, when all the particle 3-momenta lie in a plane. This result is shown to follow particularly simply from the known BCJ relations between the colour-ordered tree amplitudes, and the MHV formalism is used to express the additional kinematic constraint as a relatively simple expression in terms of only rapidity differences between the final-state partons. In addition, we find that zeros exist for non-planar configurations of the final-state partons, but for which the normal `type-I' conditions on the particle four-momenta do not generally apply. We present numerical results and comment on the possibility of observing planar radiation zeros in hadronic collisions, via central exclusive three-jet production.Comment: 22 pages, 5 figures. Version accepted for publication in JHE

Remote monitoring of biodynamic activity using electric potential sensors

Previous work in applying the electric potential sensor to the monitoring of body electrophysiological signals has shown that it is now possible to monitor these signals without needing to make any electrical contact with the body. Conventional electrophysiology makes use of electrodes which are placed in direct electrical contact with the skin. The electric potential sensor requires no cutaneous electrical contact, it operates by sensing the displacement current using a capacitive coupling. When high resolution body electrophysiology is required a strong (capacitive) coupling is used to maximise the collected signal. However, in remote applications where there is typically an air-gap between the body and the sensor only a weak coupling can be achieved. In this paper we demonstrate that the electric potential sensor can be successfully used for the remote sensing and monitoring of bioelectric activity. We show examples of heart-rate measurements taken from a seated subject using sensors mounted in the chair. We also show that it is possible to monitor body movements on the opposite side of a wall to the sensor. These sensing techniques have biomedical applications for non-contact monitoring of electrophysiological conditions and can be applied to passive through-the-wall surveillance systems for security applications

Photon-Photon Collisions with SuperChic

The SuperChic Monte Carlo generator provides a common platform for QCD-mediated, photoproduction and photon-induced Central Exclusive Production (CEP), with a fully differential treatment of soft survival effects. In these proceedings we summarise the processes generated, before discussing in more detail those due to photon-photon collisions, paying special attention to the correct treatment of the survival factor. We briefly consider the light-by-light scattering process as an example, before discussing planned extensions and refinements for the generator.Comment: 6 pages, 2 figures. Submitted to proceedings of the PHOTON 2017 conferenc

Inclusion of new LHC data in MMHT PDFs

I consider the effects of including a variety of new LHC data sets into the MMHT approach for PDF determination. I consider the impact of fitting new LHC and Tevatron data, which leads to clear improvements in some PDF uncertainties. There are specific issues with ATLAS 7 TeV jet data and I include a discussion of the treatment of correlated uncertainties and briefly the effects of NNLO corrections. I also present preliminary results with the inclusion of the high precison final ATLAS 7 TeV $W,Z$ rapidity-dependent data.Comment: 6 pages. To appear in proceedings of DIS2017 Worksho

Updates of PDFs in the MSTW framework

I present results on updates on PDFs which are obtained within the general framework which led to the MSTW2008 PDF sets. There are some theory and procedural improvements and a variety of new data sets, including many relevant up-to-date LHC data. A new set of PDFs is very close to being finalised, with no significant changes expected to the preliminary PDFs shown here.Comment: 6 pages, 6 figures,Published in PoS DIS (2014

Design, Synthesis, and Optimization of Opioid Receptor Peptidomimetics.

Opioids have been used to produce analgesia, euphoria, sleep, and relief from diarrhea and cough. However, opioid use is associated with several negative neurochemical adaptions including tolerance, dependence, and respiratory depression. Studies have shown that selective delta-opioid receptor (DOR) antagonism in the presence of a mu-opioid receptor (MOR) agonist greatly reduces the development of MOR-mediated morphine tolerance and dependence. Unfortunately, multi-drug regimens have complicated pharmacokinetics (PK) and are often impractical to implement in clinical practice due decreased patient compliance stemming from these PK issues. This work describes the design and synthesis of a peptidomimetic series of bi-functional ligands with a mixed-efficacy profile that display MOR agonism and DOR antagonism. These ligands retain the analgesic effect (mediated via MOR agonism) while reducing side effects (mediated via DOR antagonism). In particular, three parallel series of peptidomimetics series were synthesized that retain the key opioid binding elements and orientation of lead peptides, but that eliminate the metabolically labile moieties of the lead peptides, thereby creating more bioavailable ligands. The three parallel series of ligands utilized a tetrahydroquinoline (THQ) core, a tetrahydronaphthalene (THN) core, or an N-acetylated THQ core. N-acetylation increased the affinity of the peptidomimetics for DOR, without significantly altering the subnanomolar affinity and efficacy at MOR, and improved selectivity over the κ-opioid receptor (KOR). Using computational modeling, it was determined that the increase in DOR affinity could be through an interaction between the carbonyl moiety of N-acetylated group and a tyrosine residue in DOR. Additional analogue series were synthesized, including series with 1) various N-substitutions, all of which contain a carbonyl to maintain DOR affinity, 2) several methoxy and hydroxyl moieties to explore SAR, 3) stereochemistry around the THQ and THN core to explore SAR, and 4.) fluorine incorporated to increase bioavailabilty. Of all analogues synthesized and screened for in vivo activity, 54 emerged as having in vivo activity in the Warm Water Tail Withdrawal assay after intraperitoneal administration at 10 mg/kg. Importantly, this compound had a similar duration of action to morphine at the same 10 mg/kg dose and, however unlike morphine, 54 did not produce tolerance upon chronic administration.PhDMedicinal ChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/120692/1/aharland_1.pd

Sharpening mT2m_{T2} cusps: the mass determination of semi-invisibly decaying particles from a resonance

We revisit mass determination techniques for the minimum symmetric event topology, namely $X$ pair production followed by $X \to \ell N$, where $X$ and $N$ are unknown particles with the masses to be measured, and $N$ is an invisible particle, concentrating on the case where $X$ is pair produced from a resonance. We consider separate scenarios, with different initial constraints on the invisible particle momenta, and present a systematic method to identify the kinematically allowed mass regions in the $(m_N, m_X)$ plane. These allowed regions exhibit a cusp structure at the true mass point, which is equivalent to the one observed in the $m_{T2}$ endpoints in certain cases. By considering the boundary of the allowed mass region we systematically define kinematical variables which can be used in measuring the unknown masses, and find a new expression for the $m_{T2}$ variable as well as its inverse. We explicitly apply our method to the case that $X$ is pair produced from a resonance, and as a case study, we consider the process $pp \to A \to \tilde \chi_1^+ \tilde \chi_1^-$, followed by $\tilde \chi_1^\pm \to \ell^{\pm} \, \tilde \nu_{\ell}$, in the Minimal Supersymmetric Standard Model and show that our method provides a precise measurement of the chargino and sneutrino masses, $m_X$ and $m_N$, at $14 \, \mathrm{TeV}$ LHC with $300 \, \mathrm{fb}^{-1}$ luminosity.Comment: 18 pages, 13 figures, version 2 updated to JHEP 06 (2014) 17