I. A. Bertram
A5040673747- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Black Holes and Theoretical Physics
- Distributed and Parallel Computing Systems
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Advanced Data Storage Technologies
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Big Data Technologies and Applications
- Nuclear physics research studies
- Muon and positron interactions and applications
- Algorithms and Data Compression
- Magnetic confinement fusion research
- Scientific Computing and Data Management
- Advanced Queuing Theory Analysis
Lancaster University
2015-2024
Government of Catalonia
2024
A. Alikhanyan National Laboratory
2024
SR Research (Canada)
2024
Federación Española de Enfermedades Raras
2024
The University of Adelaide
2016-2023
TU Dresden
2023
Stockholm University
2005-2020
Heidelberg University
2019
Uppsala University
2012-2016
The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) 1 and sin(2)2θ(13) 0, expected number such is 1.5±0.3(syst). Under this hypothesis, probability to observe six or more candidate 7×10(-3), equivalent 2.5σ significance. At 90% C.L., are consistent 0.03(0.04) < 0.28(0.34)...
The D0 Collaboration reports on a search for the standard model top quark in pp¯ collisions at s=1.8TeV Fermilab Tevatron with an integrated luminosity of approximately 50pb−1. We have searched tt¯ production dilepton and single-lepton decay channels without tagging b-quark jets. observed 17 events expected background 3.8±0.6 events. probability upward fluctuation to produce signal is 2×10−6 (equivalent 4.6 deviations). kinematic properties excess are consistent decay. conclude that we...
The T2K experiment is a long baseline neutrino oscillation experiment. Its main goal to measure the last unknown lepton sector mixing angle θ13 by observing νe appearance in νμ beam. It also aims make precision measurement of known parameters, Δm232 and sin22θ23, via disappearance studies. Other goals include various cross-section measurements sterile searches. uses an intense proton beam generated J-PARC accelerator Tokai, Japan, composed beamline, near detector complex (ND280), far...
We report the observation of X(3872) in J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) data collected Run II D0 detector, we observe 522+/-100 candidates. The mass difference between state and is measured be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). have investigated production decay characteristics find them similar those psi(2S) state.
The T2K experiment has observed electron neutrino appearance in a muon beam produced 295 km from the Super-Kamiokande detector with peak energy of 0.6 GeV. A total 28 events were detected an distribution consistent signal, corresponding to significance 7.3σ when compared 4.92±0.55 expected background events. In Pontecorvo-Maki-Nakagawa-Sakata mixing model, signal depends on several parameters including three angles θ12, θ23, θ13, mass difference Δm232 and CP violating phase δCP. this...
We report observation of the electroweak production single top quarks in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ based on $2.3\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data collected by D0 detector Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from fragmentation $b$ quarks, we measure a cross section...
We report on a measurement of the inclusive jet cross section in pp[over ] collisions at center-of-mass energy sqrt[s]=1.96 TeV using data collected by D0 experiment Fermilab Tevatron Collider corresponding to an integrated luminosity 0.70 fb;{-1}. The cover transverse momenta from 50 600 GeV and rapidities range -2.4 2.4. Detailed studies correlations between systematic uncertainties momentum rapidity are presented, measurements found be good agreement with next-to-leading order QCD calculations.
We present a measurement of forward-backward asymmetry in top quark-antiquark production proton-antiproton collisions the final state containing lepton and at least four jets. Using dataset corresponding to an integrated luminosity $5.4\,\mathrm {fb}^{-1}$, collected by \DZ\ experiment Fermilab Tevatron Collider, we measure \ttbar\ be $(9.2 \pm 3.7)$% reconstruction level. When corrected for detector acceptance resolution, is found $(19.6 6.5)$%. also based on from quark decay, $(15.2...
We combine searches by the CDF and D0 Collaborations for associated production of a Higgs boson with $W$ or $Z$ subsequent decay to bottom-antibottom quark pair. The data, originating from Fermilab Tevatron $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, correspond integrated luminosities up $9.7\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. are conducted mass in range $100--150\text{ }\mathrm{GeV}/{c}^{2}$. observe an excess events data compared background predictions,...
The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations using an off-axis muon beam with a peak energy of about 0.6 GeV that originates at the J-PARC accelerator facility. Interactions neutrinos are observed near detectors placed 280 m from production target and far detector -- Super-Kamiokande (SK) located 295 km away. flux prediction is essential part successful interaction rates T2K important input to oscillation cross section measurements. A FLUKA GEANT3 based simulation...
New data from the T2K neutrino oscillation experiment produce most precise measurement of mixing parameter ${\ensuremath{\theta}}_{23}$. Using an off-axis beam with a peak energy 0.6 GeV and set corresponding to $6.57\ifmmode\times\else\texttimes\fi{}1{0}^{20}$ protons on target, has fit energy-dependent ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ probability determine parameters. The 68% confidence limit ${\mathrm{sin}}^{2}({\ensuremath{\theta}}_{23})$ is...
We present the first measurement of integrated forward-backward charge asymmetry in top-quark–top-antiquark pair (t¯t) production proton-antiproton (p¯p) collisions lepton+jets final state. Using a b-jet tagging algorithm and kinematic reconstruction assuming t¯t+X decay, sample 0.9 fb−1 data, collected by D0 experiment at Fermilab Tevatron Collider, is used to measure for different jet multiplicities. The result also set upper limits on via Z′ resonance.Received 7 December...
From an analysis of the flavor-tagged decay ${B}_{s}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}$ we obtain width difference between ${B}_{s}^{0}$ light and heavy mass eigenstates, $\ensuremath{\Delta}{\ensuremath{\Gamma}}_{s}=0.19\ifmmode\pm\else\textpm\fi{}0.07(\mathrm{stat}{)}_{\ensuremath{-}0.01}^{+0.02}(\mathrm{syst})\text{ }\text{ }{\mathrm{ps}}^{\ensuremath{-}1}$, $CP$-violating phase,...
We report results of a study the ${B}_{s}^{0}$ oscillation frequency using large sample semileptonic decays corresponding to approximately $1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity collected by D0 experiment at Fermilab Tevatron Collider in 2002--2006. The amplitude method gives lower limit on $14.8\text{ }{\mathrm{ps}}^{\ensuremath{-}1}$ 95% C.L. At $\ensuremath{\Delta}{m}_{s}=19\text{ }{\mathrm{ps}}^{\ensuremath{-}1}$, deviates from hypothesis $\mathcal{A}=0$...
We measure the charge asymmetry A ≡ (N++ - N--)/(N++ + N--) of like-sign dimuon events in 6.1 fb-1 pp collisions recorded with D0 detector at a center-of-mass energy square root(s) = 1.96 TeV Fermilab Tevatron collider. From we extract semileptonic b-hadron decays: A(sl)(b) -0.009 57 ± 0.002 51(stat) 0.001 46(sys). It differs by 3.2 standard deviations from model prediction A(sl)(b)(SM) (-2.3(-0.6)(+0.5)) × 10(-4), and provides first evidence anomalous CP violation mixing neutral B mesons.
We have used a sample of $\ensuremath{\gamma}+3$ jets events collected by the D0 experiment with an integrated luminosity about $1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ to determine fraction double parton scattering (${f}_{\mathrm{DP}}$) in single $p\overline{p}$ collision at $\sqrt{s}=1.96\text{ }\mathrm{TeV}$. The DP and effective cross section (${\ensuremath{\sigma}}_{\mathrm{eff}}$), process-independent scale parameter related density inside nucleon, are measured three...
The top quark is the heaviest known elementary particle, with a mass about 40 times larger than of its isospin partner, bottom quark. It decays almost 100% time to $W$ boson and Using top-antitop pairs at Tevatron proton-antiproton collider, CDF D0 Collaborations have measured quark's in different final states for integrated luminosities up $5.8\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. This paper reports on combination these measurements that results more precise value any individual...
The T2K collaboration: reports evidence for electron neutrino appearance at the atmospheric mass splitting, |\Delta m_{32}^2|=2.4x10^{-3} eV^2. An excess of interactions over background is observed from a muon beam with peak energy 0.6 GeV Super-Kamiokande (SK) detector 295 km beam's origin. Signal and predictions are constrained by data near detectors located 280 m production target. We observe 11 candidate events SK when 3.3\pm0.4(syst.) expected. background-only hypothesis rejected...
We report evidence of a narrow structure, $X(5568)$, in the decay sequence $X(5568) \rightarrow B_s^0 π^{\pm}$, $B_s^0 J/ψϕ$, $J/ψ\rightarrow μ^+ μ^-$, $ϕ\rightarrow K^+K^-$. This is for first instance hadronic state with valence quarks four different flavors. The mass and natural width this are measured to be $m = 5567.8 \pm 2.9 {\rm \thinspace (stat)} ^{+0.9}_{-1.9} (syst)}$ MeV/$c^2$ $Γ= 21.9 6.4 ^{+5.0}_{-2.5} (syst)} $ MeV/$c^2$. If B_s^* π^{\pm} γπ^{\pm}$ an unseen $γ$, $m(X(5568))$...
We combine searches by the CDF and D0 Collaborations for standard model Higgs boson with mass in range 90--200 GeV$/c^2$ produced gluon-gluon fusion, $WH$, $ZH$, $t{\bar{t}}H$, vector fusion processes, decaying $H\rightarrow b{\bar{b}}$, W^+W^-$, ZZ$, $H\rightarrow\tau^+\tau^-$, \gamma\gamma$ modes. The data correspond to integrated luminosities of up 10 fb$^{-1}$ were collected at Fermilab Tevatron $p{\bar{p}}$ collisions $\sqrt{s}=1.96$ TeV. are also interpreted context fermiophobic fourth...
We measure the charge asymmetry $A$ of like-sign dimuon events in 6.1 fb$^{-1}$ $p\bar{p}$ collisions recorded with D0 detector at a center-of-mass energy $\sqrt{s} = 1.96$ TeV Fermilab Tevatron collider. From $A$, we extract semileptonic $b$-hadron decays: $\aslb -0.00957 \pm 0.00251 ({\rm stat}) 0.00146 syst})$. This result differs by 3.2 standard deviations from model prediction $\aslb(SM) (-2.3^{+0.5}_{-0.6}) \times 10^{-4}$ and provides first evidence anomalous CP-violation mixing...
We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to ${W}^{+}{W}^{\ensuremath{-}}$. The data correspond an integrated total luminosity of 4.8 (CDF) 5.4 (D0) ${\mathrm{fb}}^{\ensuremath{-}1}$ $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ Fermilab Tevatron collider. No excess is observed above background expectation, resulting limits on production exclude standard model in mass range 162--166 GeV 95% C.L.
We present a search for charged Higgs bosons in top quark decays. analyze the \eplus, \muplus, $ee$, $eμ$, $μμ$, \etau and \mutau final states from pair production events, using data about 1${\text{fb}}^{-1}$ of integrated luminosity recorded by \dzero experiment at Fermilab Tevatron Collider. consider different scenarios possible boson decays, one where decays purely hadronically into charm strange quark, another it $τ$ lepton neutrino third both appear. extract limits on branching ratio...