A search for high-mass resonances decaying into a τ-lepton and a neutrino using proton-proton collisions at a center-of-mass energy of s=13 TeV is presented. The full run 2 data sample corresponding to an integrated...
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A search for high-mass resonances decaying into a τ-lepton and a neutrino using proton-proton collisions at a center-of-mass energy of s=13 TeV is presented. The full run 2 data sample corresponding to an integrated luminosity of 139 fb−1 recorded by the ATLAS experiment in the years 2015–2018 is analyzed. The τ-lepton is reconstructed in its hadronic decay modes and the total transverse momentum carried out by neutrinos is inferred from the reconstructed missing transverse momentum. The search for new physics is performed on the transverse mass between the τ-lepton and the missing transverse momentum. No excess of events above the Standard Model expectation is observed and upper exclusion limits are set on the W′→τν production cross section. Heavy W′ vector bosons with masses up to 5.0 TeV are excluded at 95% confidence level, assuming that they have the same couplings as the Standard Model W boson. For nonuniversal couplings, W′ bosons are excluded for masses less than 3.5–5.0 TeV, depending on the model parameters. In addition, model-independent limits on the visible cross section times branching ratio are determined as a function of the lower threshold on the transverse mass of the τ-lepton and missing transverse momentum.
A wide variety of Galactic sources show transient emission at soft and hard X-ray energies: low- and high-mass X-ray binaries containing compact objects, isolated neutron stars exhibiting extreme variability as magnet...
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A wide variety of Galactic sources show transient emission at soft and hard X-ray energies: low- and high-mass X-ray binaries containing compact objects, isolated neutron stars exhibiting extreme variability as magnetars as well as pulsar-wind nebulae. Although most of them can show emission up to MeV and/or GeV energies, many have not yet been detected in the TeV domain by Imaging Atmospheric Cherenkov Telescopes. In this paper, we explore the feasibility of detecting new Galactic transients with the Cherenkov Telescope Array Observatory (CTAO) and the prospects for studying them with Target of Opportunity observations. We show that CTAO will likely detect new sources in the TeV regime, such as the massive microquasars in the Cygnus region, low-mass X-ray binaries with low-viewing angle, flaring emission from the Crab pulsar-wind nebula or other novae explosions, among others. Since some of these sources could also exhibit emission at larger time-scales, we additionally test their detectability at longer exposures. We finally discuss the multiwavelength synergies with other instruments and large astronomical facilities.
A measurement of the ratio of the branching fractions, Rτ/e = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. Th...
A measurement of the ratio of the branching fractions, Rτ/e = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. This measurement uses pp collisions at $$ \sqrt{s} $$ = 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider during Run 2, corresponding to an integrated luminosity of 140 fb−1. The W → τντ (with τ → eνeντ) and W → eνe decays are distinguished using the differences in the impact parameter distributions and transverse momentum spectra of the electrons. The measured ratio of branching fractions Rτ/e = 0.975 ± 0.012 (stat.) ± 0.020 (syst.), is consistent with the Standard Model assumption of lepton flavour universality in W-boson decays.
The paper presents a search for supersymmetric particles produced in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV and decaying into final states with missing transverse momentum and jets originating from charm ...
The paper presents a search for supersymmetric particles produced in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV and decaying into final states with missing transverse momentum and jets originating from charm quarks. The data were taken with the ATLAS detector at the Large Hadron Collider at CERN from 2015 to 2018 and correspond to an integrated luminosity of 139 fb−1. No significant excess of events over the expected Standard Model background expectation is observed in optimized signal regions, and limits are set on the production cross-sections of the supersymmetric particles. Pair production of charm squarks or top squarks, each decaying into a charm quark and the lightest supersymmetric particle $$ {\overset{\sim }{\chi}}_1^0 $$ , is excluded at 95% confidence level for squarks with masses up to 900 GeV for scenarios where the mass of $$ {\overset{\sim }{\chi}}_1^0 $$ is below 50 GeV. Additionally, the production of leptoquarks with masses up to 900 GeV is excluded for the scenario where up-type leptoquarks decay into a charm quark and a neutrino. Model-independent limits on cross-sections and event yields for processes beyond the Standard Model are also reported.
A search for pair production of vector-like leptons coupling to first- and second-generation Standard Model leptons is presented. The search is based on a dataset of proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV...
A search for pair production of vector-like leptons coupling to first- and second-generation Standard Model leptons is presented. The search is based on a dataset of proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb−1. Events are categorised depending on the flavour and multiplicity of leptons (electrons or muons), as well as on the scores of a deep neural network targeting particular signal topologies according to the decay modes of the vector-like leptons. In each of the signal regions, the scalar sum of the transverse momentum of the leptons and the missing transverse momentum is analysed. The main background processes are estimated using dedicated control regions in a simultaneous fit with the signal regions to data. No significant excess above the Standard Model background expectation is observed and limits are set at 95% confidence level on the production cross-sections of vector-like electrons and muons as a function of the vector-like lepton mass, separately for SU(2) doublet and singlet scenarios. The resulting mass lower limits are 1220 GeV (1270 GeV) and 320 GeV (400 GeV) for vector-like electrons (muons) in the doublet and singlet scenarios, respectively.
A study of the Higgs boson decaying into bottom quarks (H → $$ b\overline{b} $$ ) and charm quarks (H → $$ c\overline{c} $$ ) is performed, in the associated production channel of the Higgs boson with a W or Z boson...
A study of the Higgs boson decaying into bottom quarks (H → $$ b\overline{b} $$ ) and charm quarks (H → $$ c\overline{c} $$ ) is performed, in the associated production channel of the Higgs boson with a W or Z boson, using 140 fb−1 of proton-proton collision data at $$ \sqrt{s} $$ = 13 TeV collected by the ATLAS detector. The individual production of WH and ZH with H → $$ b\overline{b} $$ is established with observed (expected) significances of 5.3 (5.5) and 4.9 (5.6) standard deviations, respectively. Differential cross-section measurements of the gauge boson transverse momentum within the simplified template cross-section framework are performed in a total of 13 kinematical fiducial regions. The search for the H → $$ c\overline{c} $$ decay yields an observed (expected) upper limit at 95% confidence level of 11.5 (10.6) times the Standard Model prediction. The results are also used to set constraints on the charm coupling modifier, resulting in |κc| < 4.2 at 95% confidence level. Combining the H → $$ b\overline{b} $$ and H → $$ c\overline{c} $$ measurements constrains the absolute value of the ratio of Higgs-charm and Higgs-bottom coupling modifiers (|κc/κb|) to be less than 3.6 at 95% confidence level.
Hybrid cryptosystem combines symmetric algorithms and asymmetric algorithms. This combination utilizes speeds on encryption/decryption processes of symmetric algorithms and asymmetric algorithms to secure symmetric ke...
Hybrid cryptosystem combines symmetric algorithms and asymmetric algorithms. This combination utilizes speeds on encryption/decryption processes of symmetric algorithms and asymmetric algorithms to secure symmetric keys. In this paper we propose hybrid cryptosystem that combine symmetric algorithms VMPC and asymmetric algorithms RSA – CRT optimization. RSA – CRT optimization speeds up the decryption process by obtaining plaintext with dp and p key only, so there is no need to perform CRT processes. The VMPC algorithm is more efficient in software implementation and reduces known weaknesses in RC4 key generation. The results show hybrid cryptosystem RSA – CRT optimization and VMPC is faster than hybrid cryptosystem RSA – VMPC and hybrid cryptosystem RSA – CRT – VMPC. Keyword : Cryptography, RSA, RSA – CRT, VMPC, Hybrid Cryptosystem.
The scoreboard is designed and made for a universal use that can be used in matches in some sports such as basketball, futsal, ping pong, badminton, and others. The scoreboard is designed and made based on the needs o...
The scoreboard is designed and made for a universal use that can be used in matches in some sports such as basketball, futsal, ping pong, badminton, and others. The scoreboard is designed and made based on the needs of several sports in the Student Activity Unit at HKBP Nommensen University which can be easily moved. Scores displayed on the scoreboard is not only the result of the game but also displayed time in the countdown. This scoreboard can be operated by using a cable and can also without using a cable by using a mobile phone through communication using bluetooth. This scoreboard is based on a microcontroller and uses backup power through rechargeable batteries that can be automatically charged. In trials in several games, this tool works well with a few drawbacks in case of a match that takes more than 100 minutes because the time display can only display a maximum time of 99 minutes.
Statistical combinations of searches for charginos and neutralinos using various decay channels are performed using 139 fb−1 of pp collision data at s=13 TeV with the ATLAS detector at the Large Hadron Collider. Sea...
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Statistical combinations of searches for charginos and neutralinos using various decay channels are performed using 139 fb−1 of pp collision data at s=13 TeV with the ATLAS detector at the Large Hadron Collider. Searches targeting pure-wino chargino pair production, pure-wino chargino-neutralino production, or Higgsino production decaying via standard model W, Z, or h bosons are combined to extend the mass reach to the produced supersymmetric particles by 30–100 GeV. The depth of the sensitivity of the original searches is also improved by the combinations, lowering the 95% C.L. cross-section upper limits by 15%–40%.
The associated production of Higgs and W bosons via vector-boson fusion is highly sensitive to the relative sign of the Higgs boson couplings to W and Z bosons. In this Letter, two searches for this process are presen...
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The associated production of Higgs and W bosons via vector-boson fusion is highly sensitive to the relative sign of the Higgs boson couplings to W and Z bosons. In this Letter, two searches for this process are presented, using 140 fb−1 of proton-proton collision data at s=13 TeV recorded by the ATLAS detector at the LHC. The first search targets scenarios with opposite-sign couplings of the W and Z bosons to the Higgs boson, while the second targets standard model-like scenarios with same-sign couplings. Both analyses consider Higgs boson decays into a pair of b quarks and W boson decays with an electron or muon. The data exclude the opposite-sign coupling hypothesis with a significance beyond 5σ, and the observed (expected) upper limit set on the cross section for vector-boson fusion WH production is 9.0 (8.7) times the standard model value at 95% confidence level.
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