H. Castilla-Valdez
A5017534724- 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
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Medical Imaging Techniques and Applications
- Distributed and Parallel Computing Systems
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- Noncommutative and Quantum Gravity Theories
- Muon and positron interactions and applications
- Nuclear reactor physics and engineering
- Particle accelerators and beam dynamics
- Advanced Data Storage Technologies
- Radiation Therapy and Dosimetry
- Superconducting Materials and Applications
- International Science and Diplomacy
Center for Research and Advanced Studies of the National Polytechnic Institute
2016-2025
Instituto de Estudios Avanzados
2021-2025
Instituto Politécnico Nacional
2016-2025
Institute of High Energy Physics
2015-2024
A. Alikhanyan National Laboratory
2014-2024
Bulgarian Academy of Sciences
2023-2024
University of Antwerp
2024
Ibero American University
2014-2023
Institute for High Energy Physics
2015-2020
Center for Migration Studies of New York
2020
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...
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.
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 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...
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 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 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...
We present an updated measurement of the anomalous like-sign dimuon charge asymmetry Aslb for semi-leptonic $b$-hadron decays in 9.0 fb^-1 p pbar collisions recorded with D0 detector at a center-of-mass energy sqrt{s} = 1.96 TeV Fermilab Tevatron collider. obtain (-0.787 +- 0.172(stat) 0.093 (syst))%. This result differs by 3.9 standard deviations from prediction model and provides evidence anomalously large CP violation neutral B decay. The dependence on muon impact parameter is consistent...
We present the results of a search for flavor changing neutral current decay B_s^0->mu^+mu^- using 6.1 fb^-1 ppbar collisions at sqrt(s) = 1.96 TeV collected by D0 experiment Fermilab Tevatron Collider. The observed number B_s^0 candidates is consistent with background expectations. resulting upper limit on branching fraction BR(B_s^0->mu^+mu^-) < 5.1 x 10^-8 95% C.L. This factor 2.4 better than that previous analysis and best to date.
We present a measurement of the W boson mass using data corresponding to 4.3fb^-1 integrated luminosity collected with D0 detector during Run II at Fermilab Tevatron p\bar{p} collider. With sample 1,677,394 -> e\nu candidate events, we measure M_W = 80.367 +/- 0.026 GeV. This result is combined an earlier determined independent sample, 1fb^-1 luminosity, yield 80.375 0.023
We report an updated measurement of the $CP$-violating phase, ${\ensuremath{\phi}}_{s}^{J/\ensuremath{\psi}\ensuremath{\phi}}$, and decay-width difference for two mass eigenstates, $\ensuremath{\Delta}{\ensuremath{\Gamma}}_{s}$, from flavor-tagged decay ${B}_{s}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}$. The data sample corresponds to integrated luminosity $8.0\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ accumulated with D0 detector using $p\overline{p}$ collisions...
We investigate the decay ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}{K}^{+}$ in a search for $X(4140)$ state, narrow threshold resonance $J/\ensuremath{\psi}\ensuremath{\phi}$ system. The data sample corresponds to an integrated luminosity of $10.4\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\mathrm{TeV}$ collected by D0 experiment Fermilab Tevatron collider. observe mass peak with statistical significance 3.1...
We present a measurement of the forward–backward asymmetry in top quark–antiquark production using full Tevatron Run II data set collected by D0 experiment at Fermilab. The is performed lepton+jets final states new kinematic fitting algorithm for events with four or more jets and partial reconstruction only three jets. Corrected detector acceptance resolution effects, evaluated to be AFB=(10.6±3.0)%. Results are consistent standard model predictions which range from 5.0% 8.8%. also...
We present the observation of doubly-produced $J/\psi$ mesons with D0 detector at Fermilab in $p\bar{p}$ collisions $\sqrt{s}=1.96$ TeV. The production cross section for both singly and is measured using a sample an integrated luminosity 8.1fb$^{-1}$. For first time, double separated into contributions due to single parton scatterings. Using these measurements, we determine effective $\sigma_{eff}$, parameter characterizing spatial area parton-parton interactions related density inside nucleon.
We describe an analysis comparing the $p\overline{p}$ elastic cross section as measured by D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in $pp$ collisions TOTEM 2.76, 7, 8, and 13 using model-independent approach. The sections, extrapolated $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, are compared with measurement region diffractive minimum second maximum section. two data sets disagree $3.4\ensuremath{\sigma}$ level thus provide evidence for $t$-channel exchange...
We present a measurement of the shape boson rapidity distribution for $p\overline{p}\ensuremath{\rightarrow}Z/{\ensuremath{\gamma}}^{*}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}+X$ events at center-of-mass energy 1.96 TeV. The is made with electron-positron mass $71<{M}_{ee}<111\text{ }\text{ }\mathrm{GeV}$ and uses $0.4\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data collected Fermilab Tevatron collider D0 detector. This significantly reduces uncertainties on in forward region...
The D0 Collaboration has performed a measurement of the top quark mass mt based on six candidate events for process tt¯→bW+b¯W−, where W bosons decay to eν or μν. This sample was collected during an exposure detector integrated luminosity 125pb−1 s=1.8TeVpp¯ collisions. We obtain mt=168.4±12.3(stat)±3.6(syst)GeV/c2, consistent with obtained using single-lepton events. Combination and dilepton results yields mt=172.0±7.5GeV/c2.Received 16 June...
We present a search for events consistent with the production and decay of squarks gluinos minimal supersymmetric standard model (MSSM) in D0 detector at Fermilab Tevatron $p\overline{p}$ collider. examined data containing large missing transverse energy three or more jets. observed no excess above expected yield from processes. For choice MSSM parameter values, we set lower limit 95% confidence level on mass gluino 144 GeV ${/c}^{2}$ all squark masses 212 equal masses.