K-ary n-cube based off-chip communications architecture for high-speed packet processors

We present a detailed study of Higgs boson production in association with a single top quark at the LHC, at next-to-leading order accuracy in QCD. We consider total and differential cross sections, at the parton level as well as by matching short distance events to parton showers, for both t-channel and s-channel production. We provide predictions relevant for the LHC at 13 TeV together with a thorough evaluation of the residual uncertainties coming from scale variation, parton distributions, strong coupling constant and heavy quark masses. In addition, for t-channel production, we compare results as obtained in the 4-flavour and 5-flavour schemes, pinning down the most relevant differences between them. Finally, we study the sensitivity to a non-standard-model relative phase between the Higgs couplings to the top quark and to the weak bosons

Prevalence of Chronic Cancer and No-Cancer Pain in Elderly Hospitalized Patients: Elements for the Early Assessment of Palliative Care Needs

Summary: Background: We studied prevalence of chronic pain, related or not to cancer, in elderly patients, its correlation with socio-clinical factors, and its effects on daily living, to estimate feasibility of an early assessment of palliative care needs in a non-specialist hospital setting. Methods: In this prospective study, a questionnaire concerning pain and multidimensional assessment tools were administered to patients consecutively admitted to a Department of Internal Medicine comprising a Stroke Unit. Results: One hundred patients were recruited, 38 of whom experiencing pain, chronic in 26 patients (68%). A total of 34.3% of patients with pain and 12.5% of patients without pain suffered from depression (P = 0.013). Depressed patients showed significantly higher median values in all Brief Pain Inventory (BPI) scores and items. Depressed patients also obtained less pain relief from therapies. Patients with mild dementia showed, significantly or as a trend, a higher median least, average and "pain right now" pain values. Worst pain values in the previous 24 h increased with age. Only 42% of patients reported to be on pain therapy upon admission to hospital, whereas 62% were undergoing treatment at the time of discharge. A correlation was found between the pain value and the level of interference with daily activities. Pain was mentioned in the discharge letter in 36% of cases. Conclusion: Pain is a critical underestimated problem in elderly patients. A timely systematic evaluation of the pain would call attention to palliative care needs and reduce the negative effects of uncontrolled pain on the quality of life. Keywords: Pain assessment, Pain prevalence, Elderly patients, Pain and depression, Pain and activities of daily livin

Lifting degeneracies in Higgs couplings using single top production in association with a Higgs boson

Current Higgs data show an ambiguity in the value of the Yukawa couplings to quarks and leptons. Not so much because of still large uncertainties in the measurements but as the result of several almost degenerate minima in the coupling profile likelihood function. To break these degeneracies, it is important to identify and measure processes where the Higgs coupling to fermions interferes with other coupling(s). The most prominent example, the decay of $h \to \gamma \gamma$, is not sufficient to give a definitive answer. In this Letter, we argue that $t$-channel single top production in association with a Higgs boson, with $h\to b\bar b$, can provide the necessary information to lift the remaining degeneracy in the top Yukawa. Within the Standard Model, the total rate is highly reduced due to an almost perfect destructive interference in the hard process, $W b \rightarrow t h$. We first show that for non-standard couplings the cross section can be reliably computed without worrying about corrections from physics beyond the cutoff scale $\Lambda\gtrsim 10\,\mathrm{TeV}$, and that it can be enhanced by more than one order of magnitude compared to the SM. We then study the signal $p p \rightarrow t h j (b)$ with 3 and 4 $b$'s in the final state, and its main backgrounds at the LHC. We find the 8 TeV run dataset to be sensitive to the sign of the anomalous top Yukawa coupling, while already a moderate integrated luminosity at 14 TeV should lift the degeneracy completely.Comment: 17 pages, 7 figures. v2: inclusive signal cross sections at NLO in QCD added; new comment on sensitivity of the analysis to t tbar h process. Matches version accepted by JHE

tWH associated production at the LHC

We study Higgs boson production in association with a top quark and a $W$ boson at the LHC. At NLO in QCD, $tWH$ interferes with $t\bar t H$ and a procedure to meaningfully separate the two processes needs to be employed. In order to define $tWH$ production for both total rates and differential distributions, we consider the diagram removal and diagram subtraction techniques that have been previously proposed for treating intermediate resonances at NLO, in particular in the context of $tW$ production. These techniques feature approximations that need to be carefully taken into account when theoretical predictions are compared to experimental measurements. To this aim, we first critically revisit the $tW$ process, for which an extensive literature exists and where an analogous interference with $t \bar t$ production takes place. We then provide robust results for total and differential cross sections for $tW$ and $tWH$ at 13 TeV, also matching short-distance events to a parton shower. We formulate a reliable prescription to estimate the theoretical uncertainties, including those associated to the very definition of the process at NLO. Finally, we study the sensitivity to a non-Standard-Model relative phase between the Higgs couplings to the top quark and to the $W$ boson in $tWH$ production.Comment: v3: expanded some discussions in the text, improved some plots (results unchanged

Higgs characterisation at NLO in QCD: CP properties of the top-quark Yukawa interaction

At the LHC the CP properties of the top-quark Yukawa interaction can be probed through Higgs production in gluon fusion or in association with top quarks. We consider the possibility for both CP-even and CP-odd couplings to the top quark to be present, and study CP-sensitive observables at next-to-leading order (NLO) in QCD, including parton-shower effects. We show that the inclusion of NLO corrections sizeably reduces the theoretical uncertainties, and confirm that di-jet correlations in $H+2$ jet production through gluon fusion and correlations of the top-quark decay products in $t\bar tH$ production can provide sensitive probes of the CP nature of the Higgs interactions.Comment: 18 pages, 9 figures, 12 tables; v2: references added, version to appear in EPJ

Lepton-pair production in association with a bbˉb\bar{b} pair and the determination of the WW boson mass

We perform a study of lepton-pair production in association with bottom quarks at the LHC based on the predictions obtained at next-to-leading order in QCD, both at fixed order and matched with a QCD parton shower. We consider a comprehensive set of observables and estimate the associated theoretical uncertainties by studying the dependence on the perturbative QCD scales (renormalisation, factorisation and shower) and by comparing different parton-shower models (Pythia8 and Herwig++) and matching schemes (MadGraph5_aMC@NLO and POWHEG). Based on these results, we propose a simple procedure to include bottom-quark effects in neutral-current Drell-Yan production, going beyond the standard massless approximation. Focusing on the inclusive lepton-pair transverse-momentum distribution $p_{\bot}^{l^+l^-}$, we quantify the impact of such effects on the tuning of the simulation of charged-current Drell-Yan observables and the $W$-boson mass determination.Comment: 47 pages, 29 figures, 1 tabl

Resummation effects in the bottom-quark fragmentation function

We compute the perturbative component of the fragmentation function of the b quark to the best of the present theoretical knowledge. The fixed-order calculation to order alpha(2)(s) of the fragmentation function at the initial scale is matched with soft-emission logarithm resummation to next-to-next-to-leading logarithmic accuracy, so that order-alpha(2)(s) corrections are accounted for exactly, and logarithmically enhanced contributions from loops of b quarks are included. This requires the calculation of the Mellin transform of the order-alpha(2)(s) result in the whole complex plane for the Mellin variable, which we provide for the first time for all the fragmenting partons. Evolution is performed to next-to-next-to-leading log accuracy, and mixing with the gluon fragmentation function is taken into account. The perturbative fragmentation functions are made available via LHAPDF grids

Single top production in association with a WZ pair at the LHC in the SMEFT

We study single top quark production in association with a WZ pair at the LHC in the context of the Standard Model (SM) and the Standard Model Effective Field Theory (SMEFT). A significant advantage of tWZ compared to other EW top production processes is its sensitivity to unitarity-violating behaviour induced in its 2 → 2 sub-amplitudes through modified EW interactions. At NLO in QCD, tWZ interferes with tt‾ overline{t} tZ and tt‾ overline{t} t and a method to meaningfully separate it from these overlapping processes needs to be employed. In order to define tWZ production for total rates and differential distributions, we consider the approaches proposed in the literature for similar cases and find that diagram-removal procedures provide reliable results both for the SM and the SMEFT in a suitably defined phase-space region. We provide robust results for total and differential cross sections for tWZ at 13 TeV, including the six relevant dimension-6 operators (OtW mathcal{O} _{tW}OtW​,OtZ mathcal{O} _{tZ}OtZ​,OtG mathcal{O} _{tG}OtG​,OφQ(−) {mathcal{O}}_{arphi Q}^{left(- ight)} OφQ(−)​,OφQ(3) {mathcal{O}}_{arphi Q}^{(3)} OφQ(3)​,Oφt mathcal{O} _{φt}Oφt​), also matching short-distance events to parton shower

Double fermiophobic Higgs boson production at the LHC and LC

We consider the phenomenology of a fermiophobic Higgs boson (h_f) at the Large Hadron Collider (LHC) and a e+e- Linear Collider (LC). At both machines the standard production mechanisms which rely on the coupling h_fVV (V=W,Z) can be very suppressed at large tan beta. In such cases the complementary channels pp to H^\pm h_f, A^0 h_f and e+e- to A^0 h_f offer promising cross-sections. Together with the potentially large branching ratios for H^\pm to h_fW* and A^0 to h_fZ*, these mechanisms would give rise to double h_f production, leading to signatures of gamma gamma gamma gamma, gamma gamma VV and VVVV.Comment: 19 pages, 9 figures, expanded discussion, fig.1 changed slightly, version to appear in Phys.Rev.