Triphoton production at hadron colliders

We present next-to-leading order predictions for the production of triphoton final states at the LHC and the Tevatron. Our results include the effect of photon fragmentation for the first time and we are able to quantify the impact of different isolation prescriptions. We find that calculations accounting for fragmentation effects at leading order, and those employing a smooth cone isolation where no fragmentation contribution is required, are in reasonable agreement with one another. However, larger differences in the predicted rates arise when higher order corrections to the fragmentation functions are included. In addition we present full analytic results for the $\gamma\gamma\gamma$ and $\gamma\gamma+$jet one-loop amplitudes. These amplitudes, which are particularly compact, may be useful to future higher-order calculations. Our results are available in the Monte Carlo code MCFM.Comment: 16 pages, 4 figure

ZγZ\gamma production at NNLO including anomalous couplings

In this paper we present a next-to-next-to-leading order (NNLO) QCD calculation of the processes $pp\rightarrow l^+l^-\gamma$ and $pp\rightarrow \nu\bar\nu\gamma$ that we have implemented in MCFM. Our calculation includes QCD corrections at NNLO both for the Standard Model (SM) and additionally in the presence of $Z\gamma\gamma$ and $ZZ\gamma$ anomalous couplings. We compare our implementation, obtained using the jettiness slicing approach, with a previous SM calculation and find broad agreement. Focusing on the sensitivity of our results to the slicing parameter, we show that using our setup we are able to compute NNLO cross sections with numerical uncertainties of about $0.1\%$, which is small compared to residual scale uncertainties of a few percent. We study potential improvements using two different jettiness definitions and the inclusion of power corrections. At $\sqrt{s}=13$ TeV we present phenomenological results and consider $Z\gamma$ as a background to $H\to Z\gamma$ production. We find that, with typical cuts, the inclusion of NNLO corrections represents a small effect and loosens the extraction of limits on anomalous couplings by about $10\%$.Comment: 30 pages, 14 figure

NLO predictions for a lepton, missing transverse momentum and dijets at the Tevatron

n this letter we investigate the various processes that can contribute to a final state consisting of a lepton, missing transverse momentum and two jets at Next to Leading Order (NLO) at the Tevatron. In particular we consider the production of W/Z + 2 jets, diboson pairs, single top and the tt process with both fully leptonic and semi-leptonic decays. We present distributions for the invariant mass of the dijet system and normalisations of the various processes, accurate to NLO.Comment: 4 pages, 5 figure

Hadronic production of a Higgs boson and two jets at next-to-leading order

We perform an update of the next-to-leading order calculation of the rate for Higgs boson production in association with two jets. Our new calculation incorporates the full analytic result for the one-loop virtual amplitude. This new theoretical information allows us to construct a code including the decay of the Higgs boson without incurring a prohibitive penalty in computer running time. Results are presented for the Tevatron, where implications for the Higgs search are sketched, and also for a range of scenarios at the LHC.Comment: 16 pages, 4 figure

FS ≠ FS (Formulaicity and Prosody)

Research in recent years has convincingly shown the importance in informal speech of formulaic sequences (FSs), or pre-fabricated linguistic segments. Work being undertaken at the Technological University Dublin (DIT) aims to extend research into FSs by including the aspect of prosody. In this presentation we outline the construction of a novel speech corpus at DIT, based on intelligent access to natural dialogue recorded at a high audio quality. Search strings can be examined in their phonetic and dialogic context, and what Cauldwell called the ‘acoustic blur of speech’ made accessible to learner and researcher alike by means of DIT’s slow-down technology. This learning and research asset allows informal speech to be studied as a dynamic phenomenon rather than via the static record of transcription. The presenters will discuss initial findings of the effectiveness of DIT’s slow-down technology with Chinese learners of English, specifically in the area of formulaic sequences. We examine the role of technology in bridging the intonational gap between Mandarin prosody, which is mainly concerned with lexical demarcation, and English prosody, which works in larger units. We also demonstrate the effect of speed of delivery and pitch range on FSs as they are spoken, and how their communicative function changes with lower speech rates and increased tonal range. The presentation will round off by locating the DIT corpus in the context of existing corpora and its relevance to language learners, linguistic researchers and materials developers

The Need for a Speech Corpus

This paper outlines the ongoing construction of a speech corpus for use by applied linguists and advanced EFL/ESL students. The first section establishes the need for improvements in the teaching of listening skills and pronunciation practice for EFL/ESL students. It argues for the need to use authentic native-to-native speech in the teaching/learning process so as to promote social inclusion and contextualises this within the literature, based mainly on the work of Swan, Brown and McCarthy. The second part addresses features of native speech flow which cause difficulties for EFL/ESL students (Brown, Cauldwell) and establishes the need for improvements in the teaching of listening skills. Examples are given of reduced forms characteristic of relaxed native speech, and how these can be made accessible for study using the Technological University Dublin’s slow-down technology, which gives students more time to study native speech features, without tonal distortion. The final section introduces a novel Speech Corpus being developed at DIT. It shows the limits of traditional corpora and outlines the general requirements of a Speech Corpus. This tool–which will satisfy the needs of teachers, learners and researchers–will link digitally recorded, natural, native-to-native speech so that each transcript segment will be linked to its associated sound file. Users will be able to locate desired speech strings, play, compare and contrast them—and slow them down for more detailed study

Associated production of a Higgs boson at NNLO

In this paper we present a Next-to-Next-to Leading Order (NNLO) calculation of the production of a Higgs boson in association with a massive vector boson. We include the decays of the unstable Higgs and vector bosons, resulting in a fully flexible parton-level Monte Carlo implementation. We also include all O(α2s) contributions that occur in production for these processes: those mediated by the exchange of a single off-shell vector boson in the s-channel, and those which arise from the coupling of the Higgs boson to a closed loop of fermions. We study final states of interest for Run II phenomenology, namely H→bb¯¯ , γγ and WW ∗. The treatment of the H→bb¯¯ decay includes QCD corrections at NLO. We use the recently developed N -jettiness regularization procedure, and study its viability in the presence of a large final-state phase space by studying pp → V (H → WW ∗) → leptons