133,603 research outputs found

    Heaviest Induced Ancestors and Longest Common Substrings

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    Suppose we have two trees on the same set of leaves, in which nodes are weighted such that children are heavier than their parents. We say a node from the first tree and a node from the second tree are induced together if they have a common leaf descendant. In this paper we describe data structures that efficiently support the following heaviest-induced-ancestor query: given a node from the first tree and a node from the second tree, find an induced pair of their ancestors with maximum combined weight. Our solutions are based on a geometric interpretation that enables us to find heaviest induced ancestors using range queries. We then show how to use these results to build an LZ-compressed index with which we can quickly find with high probability a longest substring common to the indexed string and a given pattern

    Heavy Higgs Bosons at 14 TeV and 100 TeV

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    Searching for Higgs bosons beyond the Standard Model (BSM) is one of the most important missions for hadron colliders. As a landmark of BSM physics, the MSSM Higgs sector at the LHC is expected to be tested up to the scale of the decoupling limit of O(1) TeV, except for a wedge region centered around tanβ310\tan\beta \sim 3 -10, which has been known to be difficult to probe. In this article, we present a dedicated study testing the decoupled MSSM Higgs sector, at the LHC and a next-generation pppp-collider, proposing to search in channels with associated Higgs productions, with the neutral and charged Higgs further decaying into tttt and tbtb, respectively. In the case of neutral Higgs we are able to probe for the so far uncovered wedge region via ppbbH/Abbttpp\to bb H/A \to bbtt. Additionally, we cover the the high tanβ\tan\beta range with ppbbH/Abbττpp\to bb H/A \to bb\tau\tau. The combination of these searches with channels dedicated to the low tanβ\tan\beta region, such as ppH/Attpp\to H/A \to tt and ppttH/Attttpp\to tt H/A \to tttt potentially covers the full tanβ\tan\beta range. The search for charged Higgs has a slightly smaller sensitivity for the moderate tanβ\tan\beta region, but additionally probes for the higher and lower tanβ\tan\beta regions with even greater sensitivity, via pptbH±tbtbpp\to tb H^\pm \to tbtb. While the LHC will be able to probe the whole tanβ\tan\beta range for Higgs masses of O(1) TeV by combining these channels, we show that a future 100 TeV pppp-collider has a potential to push the sensitivity reach up to O(10)\sim \mathcal O(10) TeV. In order to deal with the novel kinematics of top quarks produced by heavy Higgs decays, the multivariate Boosted Decision Tree (BDT) method is applied in our collider analyses. The BDT-based tagging efficiencies of both hadronic and leptonic top-jets, and their mutual fake rates as well as the faking rates by other jets (hh, ZZ, WW, bb, etc.) are also presented.Comment: published versio

    Maximum Inner-Product Search using Tree Data-structures

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    The problem of {\em efficiently} finding the best match for a query in a given set with respect to the Euclidean distance or the cosine similarity has been extensively studied in literature. However, a closely related problem of efficiently finding the best match with respect to the inner product has never been explored in the general setting to the best of our knowledge. In this paper we consider this general problem and contrast it with the existing best-match algorithms. First, we propose a general branch-and-bound algorithm using a tree data structure. Subsequently, we present a dual-tree algorithm for the case where there are multiple queries. Finally we present a new data structure for increasing the efficiency of the dual-tree algorithm. These branch-and-bound algorithms involve novel bounds suited for the purpose of best-matching with inner products. We evaluate our proposed algorithms on a variety of data sets from various applications, and exhibit up to five orders of magnitude improvement in query time over the naive search technique.Comment: Under submission in KDD 201

    Next-to-leading order QCD corrections to Higgs boson production in association with a photon via weak-boson fusion at the LHC

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    Higgs boson production in association with a hard central photon and two forward tagging jets is expected to provide valuable information on Higgs boson couplings in a range where it is difficult to disentangle weak-boson fusion processes from large QCD backgrounds. We present next-to-leading order QCD corrections to Higgs production in association with a photon via weak-boson fusion at a hadron collider in the form of a flexible parton-level Monte Carlo program. The QCD corrections to integrated cross sections are found to be small for experimentally relevant selection cuts, while the shape of kinematic distributions can be distorted by up to 20% in some regions of phase space. Residual scale uncertainties at next-to-leading order are at the few-percent level.Comment: 17 pages, 7 figures, 1 tabl

    Faster tuple lattice sieving using spherical locality-sensitive filters

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    To overcome the large memory requirement of classical lattice sieving algorithms for solving hard lattice problems, Bai-Laarhoven-Stehl\'{e} [ANTS 2016] studied tuple lattice sieving, where tuples instead of pairs of lattice vectors are combined to form shorter vectors. Herold-Kirshanova [PKC 2017] recently improved upon their results for arbitrary tuple sizes, for example showing that a triple sieve can solve the shortest vector problem (SVP) in dimension dd in time 20.3717d+o(d)2^{0.3717d + o(d)}, using a technique similar to locality-sensitive hashing for finding nearest neighbors. In this work, we generalize the spherical locality-sensitive filters of Becker-Ducas-Gama-Laarhoven [SODA 2016] to obtain space-time tradeoffs for near neighbor searching on dense data sets, and we apply these techniques to tuple lattice sieving to obtain even better time complexities. For instance, our triple sieve heuristically solves SVP in time 20.3588d+o(d)2^{0.3588d + o(d)}. For practical sieves based on Micciancio-Voulgaris' GaussSieve [SODA 2010], this shows that a triple sieve uses less space and less time than the current best near-linear space double sieve.Comment: 12 pages + references, 2 figures. Subsumed/merged into Cryptology ePrint Archive 2017/228, available at https://ia.cr/2017/122

    Probing new physics with displaced vertices: muon tracker at CMS

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    Long-lived particles can manifest themselves at the LHC via "displaced vertices" - several charged tracks originating from a position separated from the proton interaction point by a macroscopic distance. Here we demonstrate a potential of the muon trackers at the CMS experiment for displaced vertex searches. We use heavy neutral leptons and Chern-Simons portal as two examples of long-lived particles for which the CMS muon tracker can provide essential information about their properties.Comment: Journal versio
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