Dijet events are studied in the proton-proton collision data set recorded at s=13 TeV with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, corresponding to integrated luminosities of 3.5 fb−1 and 3...
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Dijet events are studied in the proton-proton collision data set recorded at s=13 TeV with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, corresponding to integrated luminosities of 3.5 fb−1 and 33.5 fb−1 respectively. Invariant mass and angular distributions are compared to background predictions and no significant deviation is observed. For resonance searches, a new method for fitting the background component of the invariant mass distribution is employed. The data set is then used to set upper limits at a 95% confidence level on a range of new physics scenarios. Excited quarks with masses below 6.0 TeV are excluded, and limits are set on quantum black holes, heavy W′ bosons, W* bosons, and a range of masses and couplings in a Z′ dark matter mediator model. Model-independent limits on signals with a Gaussian shape are also set, using a new approach allowing factorization of physics and detector effects. From the angular distributions, a scale of new physics in contact interaction models is excluded for scenarios with either constructive or destructive interference. These results represent a substantial improvement over those obtained previously with lower integrated luminosity.
A search for dark matter in association with a Higgs boson decaying to two photons is presented. This study is based on data collected with the ATLAS detector, corresponding to an integrated luminosity of 36.1 fb−1 o...
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A search for dark matter in association with a Higgs boson decaying to two photons is presented. This study is based on data collected with the ATLAS detector, corresponding to an integrated luminosity of 36.1 fb−1 of proton-proton collisions at the LHC at a center-of-mass energy of 13 TeV in 2015 and 2016. No significant excess over the expected background is observed. Upper limits at 95% confidence level are set on the visible cross section for beyond the Standard Model physics processes, and the production cross section times branching fraction of the Standard Model Higgs boson decaying into two photons in association with missing transverse momentum in three different benchmark models. Limits at 95% confidence level are also set on the observed signal in two-dimensional mass planes. Additionally, the results are interpreted in terms of 90% confidence-level limits on the dark-matter–nucleon scattering cross section, as a function of the dark-matter particle mass, for a spin-independent scenario.
A measurement of the production cross section for two isolated photons in proton-proton collisions at a center-of-mass energy of s=8 TeV is presented. The results are based on an integrated luminosity of 20.2 fb−1 r...
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A measurement of the production cross section for two isolated photons in proton-proton collisions at a center-of-mass energy of s=8 TeV is presented. The results are based on an integrated luminosity of 20.2 fb−1 recorded by the ATLAS detector at the Large Hadron Collider. The measurement considers photons with pseudorapidities satisfying |ηγ|<1.37 or 1.56<|ηγ|<2.37 and transverse energies of respectively ET,1γ>40 GeV and ET,2γ>30 GeV for the two leading photons ordered in transverse energy produced in the interaction. The background due to hadronic jets and electrons is subtracted using data-driven techniques. The fiducial cross sections are corrected for detector effects and measured differentially as a function of six kinematic observables. The measured cross section integrated within the fiducial volume is 16.8±0.8 pb. The data are compared to fixed-order QCD calculations at next-to-leading-order and next-to-next-to-leading-order accuracy as well as next-to-leading-order computations including resummation of initial-state gluon radiation at next-to-next-to-leading logarithm or matched to a parton shower, with relative uncertainties varying from 5% to 20%.
A measurement of the inclusive pp→tt¯+X production cross section in the τ+jets final state using only the hadronic decays of the τ lepton is presented. The measurement is performed using 20.2 fb−1 of proton-p...
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A measurement of the inclusive pp→tt¯+X production cross section in the τ+jets final state using only the hadronic decays of the τ lepton is presented. The measurement is performed using 20.2 fb−1 of proton-proton collision data recorded at a center-of-mass energy of s=8 TeV with the ATLAS detector at the Large Hadron Collider. The cross section is measured via a counting experiment by imposing a set of selection criteria on the identification and kinematic variables of the reconstructed particles and jets, and on event kinematic variables and characteristics. The production cross section is measured to be σtt¯=239±29 pb, which is in agreement with the measurements in other final states and the theoretical predictions at this center-of-mass energy.
Measurements of ZZ production in the ℓ+ℓ−ℓ′+ℓ′− channel in proton–proton collisions at 13 TeV center-of-mass energy at the Large Hadron Collider are presented. The data correspond to 36.1 fb−1 of collisions collec...
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Measurements of ZZ production in the ℓ+ℓ−ℓ′+ℓ′− channel in proton–proton collisions at 13 TeV center-of-mass energy at the Large Hadron Collider are presented. The data correspond to 36.1 fb−1 of collisions collected by the ATLAS experiment in 2015 and 2016. Here ℓ and ℓ′ stand for electrons or muons. Integrated and differential ZZ→ℓ+ℓ−ℓ′+ℓ′− cross sections with Z→ℓ+ℓ− candidate masses in the range of 66 GeV to 116 GeV are measured in a fiducial phase space corresponding to the detector acceptance and corrected for detector effects. The differential cross sections are presented in bins of twenty observables, including several that describe the jet activity. The integrated cross section is also extrapolated to a total phase space and to all standard model decays of Z bosons with mass between 66 GeV and 116 GeV, resulting in a value of 17.3±0.9[±0.6(stat)±0.5(syst)±0.6(lumi)] pb. The measurements are found to be in good agreement with the standard model. A search for neutral triple gauge couplings is performed using the transverse momentum distribution of the leading Z boson candidate. No evidence for such couplings is found and exclusion limits are set on their parameters.
Algorithms are the foundation of computerscience and engineering, which instruct the computer to do the required task efficiently. Design and Analysis of Algorithms (DAA) course is aimed to develop problem solving sk...
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Algorithms are the foundation of computerscience and engineering, which instruct the computer to do the required task efficiently. Design and Analysis of Algorithms (DAA) course is aimed to develop problem solving skills, choose appropriate design strategy and analyze given algorithm for its performance in the student community. In this paper authors propose active learning methodologies like Manifold Problem Assignment, Inspection of Algorithms, technique based Learning, Identification and Designing Method and Realization of Algorithm to meet above mentioned objectives. Since the course is taught along with tutorial, different set of problems are given across the batches to develop and analyze an algorithm by choosing appropriate design technique. Tests are conducted on each design strategy, which helped the students to apply them to the design process. At the end of the semester students are given set of problems, where they are expected to choose suitable design strategy like divide and conquer, decrease and conquer and transform and conquer to write and analyze the algorithm. Through this pedagogical activity, the Program Outcomes 3a and 3c of AbET 3a-3k are achieved. 70% of learners strongly agreed that their problem solving ability is enhanced and 30% of learners agreed that there is an improvement in algorithm design ability.
Wireless Mesh Network is one of the budding technologies in wireless networks. Routing in WMN is complicated and unpredictable than wired network, due to unstable link states and interference between neighbor routers....
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Wireless Mesh Network is one of the budding technologies in wireless networks. Routing in WMN is complicated and unpredictable than wired network, due to unstable link states and interference between neighbor routers. Since WMN is supporting hybrid architecture, a primitive metric like hop count is not efficient to route the information in the network. The Expected Transmission count (ETX) is radio based metric and it reveals the link conditions in the form of delay, loss of packets and bandwidth etc. It uses cross layer approach to direct the data by considering asymmetric nature of wireless links in WMN and captures the link state through the number of retransmissions. Thus ETX forwards the data based on link quality (or state) and provides effective communication between routers. Hybrid Wireless Mesh Protocol (HWMP) is based on IEEE 802.11s and it is prominent protocol for hybrid WMN. The authors aspire to provide effective communication in WMN using link state based metric ETX. This paper discusses about the HWMP with ETX (HWMP-ETX) and analyses the performance of WMN using end-to-end delay and good put parameters. The results show that considerable improvement exists in all the above mentioned parameters by using HWMP-ETX than HWMP with hop count.
Wireless Mesh Network (WMN) is one of the prominent technologies in the wireless network field. The main goal of WMN is to serve the large community of users with available bandwidth. Hyacinth multichannel architectur...
Wireless Mesh Network (WMN) is one of the prominent technologies in the wireless network field. The main goal of WMN is to serve the large community of users with available bandwidth. Hyacinth multichannel architecture is preferable solution for WMN to lever the substantial data and to employ the bandwidth efficiently. The performance of WMN is also depending on the routing protocol to forward the data in the network. The AODV is the most common routing protocol of wireless network technologies and it uses hop count as routing metric. This traditional routing metric is incapable to perform well in multichannel environment. Weighted Cumulative Expected Transmission Time (WCETT) routing metric is well suited for multichannel WMN. In this paper we analyze the performance of Hybrid Multichannel WMN. Two channels are assigned to the nodes and IEEE 802.11 channel assignment strategy is used by HMWMN. Throughput and drop of packets parameters are compared with single channel WMN and HMWMN by varying packet size. We conduct the Chi square test to show the relationship between packet size and throughput. Our results show that HMWMN improves the throughput by 46% and minimizes the drop of packets by 62% than the single channel. HMWMN uses WCETT routing metrics and it is compared against hop count by varying the size of network. Outcomes illustrate that HMWMN has better throughput and End-to-end delay even for large WMN.
This Letter presents a measurement of the inelastic proton-proton cross section using 60 μb−1 of pp collisions at a center-of-mass energy s of 13 TeV with the ATLAS detector at the LHC. Inelastic interactions are se...
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This Letter presents a measurement of the inelastic proton-proton cross section using 60 μb−1 of pp collisions at a center-of-mass energy s of 13 TeV with the ATLAS detector at the LHC. Inelastic interactions are selected using rings of plastic scintillators in the forward region (2.07<|η|<3.86) of the detector. A cross section of 68.1±1.4 mb is measured in the fiducial region ξ=MX2/s>10−6, where MX is the larger invariant mass of the two hadronic systems separated by the largest rapidity gap in the event. In this ξ range the scintillators are highly efficient. For diffractive events this corresponds to cases where at least one proton dissociates to a system with MX>13 GeV. The measured cross section is compared with a range of theoretical predictions. When extrapolated to the full phase space, a cross section of 78.1±2.9 mb is measured, consistent with the inelastic cross section increasing with center-of-mass energy.
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