19,435 research outputs found

    The Case for Future Hadron Colliders From B→K(∗)μ+μ−B \to K^{(*)} \mu^+ \mu^- Decays

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    Recent measurements in B→K(∗)μ+μ−B \to K^{(*)} \mu^+ \mu^- decays are somewhat discrepant with Standard Model predictions. They may be harbingers of new physics at an energy scale potentially accessible to direct discovery. We estimate the sensitivity of future hadron colliders to the possible new particles that may be responsible for the anomalies: leptoquarks or Z′Z^\primes. We consider luminosity upgrades for a 14 TeV LHC, a 33 TeV LHC, and a 100 TeV pppp collider such as the FCC-hh. Coverage of Z′Z^\prime models is excellent: for narrow particles, with perturbative couplings that may explain the bb-decay results for Z′Z^\prime masses up to 20 TeV, a 33 TeV 1 ab−1^{-1} LHC is expected to cover most of the parameter space up to 8 TeV in mass, whereas the 100 TeV FCC-hh with 10 ab−1^{-1} will cover all of it. A smaller portion of the leptoquark parameter space is covered by future colliders: for example, in a μ+μ−jj\mu^+\mu^-jj di-leptoquark search, a 100 TeV 10 ab−1^{-1} collider has a projected sensitivity up to leptoquark masses of 12 TeV (extendable to 21 TeV with a strong coupling for single leptoquark production), whereas leptoquark masses up to 41 TeV may in principle explain the anomalies.Comment: 24 pages, 10 figures. v2: Improved discussion and references added, version submitted to JHE

    Hadron Collider Sensitivity to Fat Flavourful Z′Z^\primes for RK(∗)R_{K^{(\ast)}}

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    We further investigate the case where new physics in the form of a massive Z′Z^\prime particle explains apparent measurements of lepton flavour non-universality in B→K(∗)l+l−B \rightarrow K^{(\ast)} l^+ l^- decays. Hadron collider sensitivities for direct production of such Z′Z^\primes have been previously studied in the narrow width limit for a μ+μ−\mu^+ \mu^- final state. Here, we extend the analysis to sizeable decay widths and improve the sensitivity estimate for the narrow width case. We estimate the sensitivities of the high luminosity 14 TeV Large Hadron Collider (HL-LHC), a high energy 27 TeV LHC (HE-LHC), as well as a potential 100 TeV future circular collider (FCC). The HL-LHC has sensitivity to narrow Z′Z^\prime resonances consistent with the anomalies. In one of our simplified models the FCC could probe 23 TeV Z′Z^\prime particles with widths of up to 0.35 of their mass at 95\% confidence level (CL). In another model, the HL-LHC and HE-LHC cover sizeable portions of parameter space, but the whole of perturbative parameter space can be covered by the FCC.Comment: 24 pages, 11 figures; v2 Reference

    An opioid-like system regulating feeding behavior in C. elegans

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    Neuropeptides are essential for the regulation of appetite. Here we show that neuropeptides could regulate feeding in mutants that lack neurotransmission from the motor neurons that stimulate feeding muscles. We identified nlp-24 by an RNAi screen of 115 neuropeptide genes, testing whether they affected growth. NLP-24 peptides have a conserved YGGXX sequence, similar to mammalian opioid neuropeptides. In addition, morphine and naloxone respectively stimulated and inhibited feeding in starved worms, but not in worms lacking NPR-17, which encodes a protein with sequence similarity to opioid receptors. Opioid agonists activated heterologously expressed NPR-17, as did at least one NLP-24 peptide. Worms lacking the ASI neurons, which express npr-17, did not response to naloxone. Thus, we suggest that Caenorhabditis elegans has an endogenous opioid system that acts through NPR-17, and that opioids regulate feeding via ASI neurons. Together, these results suggestC. elegans may be the first genetically tractable invertebrate opioid model

    Spatio-Temporal Sentiment Hotspot Detection Using Geotagged Photos

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    We perform spatio-temporal analysis of public sentiment using geotagged photo collections. We develop a deep learning-based classifier that predicts the emotion conveyed by an image. This allows us to associate sentiment with place. We perform spatial hotspot detection and show that different emotions have distinct spatial distributions that match expectations. We also perform temporal analysis using the capture time of the photos. Our spatio-temporal hotspot detection correctly identifies emerging concentrations of specific emotions and year-by-year analyses of select locations show there are strong temporal correlations between the predicted emotions and known events.Comment: To appear in ACM SIGSPATIAL 201

    The properties of active galaxies at the extreme of eigenvector 1

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    Eigenvector 1 (EV1) is the formal parameter which allows the introduction of some order in the properties of the unobscured type 1 active galaxies. We aim to understand the nature of this parameter by analyzing the most extreme examples of quasars with the highest possible values of the corresponding eigenvalues RFeR_{Fe}. We selected the appropriate sources from the Sloan Digital Sky Survey (SDSS) and performed detailed modeling, including various templates for the Fe II pseudo-continuum and the starlight contribution to the spectrum. Out of 27 sources with RFeR_{Fe} larger than 1.3 and with the measurement errors smaller than 20\% selected from the SDSS quasar catalog, only six sources were confirmed to have a high value of RFeR_{Fe}, defined as being above 1.3. All other sources have anRFean R_{Fe} of approximately 1. Three of the high RFeR_{Fe} objects have a very narrow Hβ\beta line, below 2100 km s−1^{-1} but three sources have broad lines, above 4500 km s−1^{-1}, that do not seem to form a uniform group, differing considerably in black hole mass and Eddington ratio; they simply have a very similar EW([OIII]5007) line. Therefore, the interpretation of the EV1 remains an open issue.Comment: Astronomy and Astrophysics (in press
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