M. Franco Sevilla
A5086859626- 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
- Medical Imaging Techniques and Applications
- Black Holes and Theoretical Physics
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Superconducting Materials and Applications
- Astrophysics and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Advanced Data Storage Technologies
- Distributed and Parallel Computing Systems
- International Science and Diplomacy
- Radiation Therapy and Dosimetry
- Gamma-ray bursts and supernovae
- Stochastic processes and statistical mechanics
- Markov Chains and Monte Carlo Methods
- Quantum chaos and dynamical systems
- Nuclear reactor physics and engineering
University of Maryland, College Park
2019-2025
University of Maryland Extension
2025
University of California, Santa Barbara
2013-2023
Tsinghua University
2023
Los Alamos National Laboratory
2023
University of Bonn
2022
Institute of High Energy Physics
2014-2019
Florida State University
2016
University of California, San Diego
2015
SLAC National Accelerator Laboratory
2009-2014
Based on the full BaBar data sample, we report improved measurements of ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B l Nu), where is either e or mu. These are sensitive to new physics contributions in form a charged Higgs boson. We measure R(D) 0.440 +- 0.058 0.042 and R(D*) 0.332 0.024 0.018, which exceed Standard Model expectations by 2.0 sigma 2.7 sigma, respectively. Taken together, our results disagree with these at 3.4 level. This excess cannot be explained boson type II two-Higgs-doublet...
Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce light mediator, so-called photon (A′), connecting sector to standard model. We present search for reaction e+e−→γA′, A′→e+e−, μ+μ− using 514 fb−1 data collected with BABAR detector. observe no statistically significant deviations from model predictions, and we set 90% confidence level upper limits on mixing strength between at 10−4−10−3...
We search for the flavor-changing neutral-current decays $B\ensuremath{\rightarrow}{K}^{(*)}\ensuremath{\nu}\overline{\ensuremath{\nu}}$, and invisible $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ via $B\ensuremath{\rightarrow}{K}^{(*)}J/\ensuremath{\psi}$ $B\ensuremath{\rightarrow}{K}^{(*)}\ensuremath{\psi}(2S)$, respectively, using a data sample of...
The process e+e- --> p anti-p gamma is studied using 469 fb-1 of integrated luminosity collected with the BABAR detector at PEP-II collider, an center-of-mass energy 10.6 GeV. From analysis invariant mass spectrum, dependence cross section for measured from threshold to 4.5 ratio electric and magnetic form factors, |G_E/G_M|, asymmetry in proton angular distribution are masses below 3 We also measure branching fractions decays J/psi psi(2S) anti p.
We present measurements of Collins asymmetries in the inclusive process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}X$, where $\ensuremath{\pi}$ stands for charged pions, at a center-of-mass energy 10.6 GeV. use data sample $468\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected by BABAR experiment PEP-II $B$ factory SLAC, and consider pairs pions produced opposite hemispheres hadronic events. observe clear distributions azimuthal angles two...
While searches for interactions at high-energy experiments have yielded more stringent bounds on new physics, the discovery potential of indirect has drawn renewed attention. The standard model predicts that physical processes involving charged leptons should feature lepton flavor universality relations among observables. Observation violation would thus establish presence physics beyond model. This article provides a review in semileptonic $b$-hadron decays. It investigates current...
A precise measurement of the cross section for process e+e−→K+K−(γ) from threshold to an energy 5 GeV is obtained with initial-state radiation (ISR) method using 232 fb−1 data collected BABAR detector at e+e− center-of-mass energies near 10.6 GeV. The uses effective ISR luminosity determined e+e−→μ+μ−(γ)γISR same set. corresponding lowest-order contribution hadronic vacuum polarization term in muon magnetic anomaly found be aμKK,LO=(22.93±0.18stat±0.22syst)×10−10. charged kaon form factor...
The ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}p\overline{p}$ cross section and the proton magnetic form factor have been measured in center-of-mass energy range from 3.0 to 6.5 GeV using initial-state radiation technique with an undetected photon. This is first measurement of at energies higher than 4.5 GeV. analysis based on $469\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity collected BABAR detector PEP-II collider ${e}^{+}{e}^{\ensuremath{-}}$ near 10.6...
Inclusive production cross sections of $\pi^\pm$, $K^\pm$ and $p\bar{p}$ per hadronic $e^+e^-$ annihilation event in are measured at a center-of-mass energy 10.54 GeV, using relatively small sample very high quality data from the BaBar experiment PEP-II $B$-factory SLAC National Accelerator Laboratory. The drift chamber Cherenkov detector provide clean samples identified over wide range momenta. Since is below threshold to produce $B\bar{B}$ pair, with $B$ bottom-quark meson, these represent...
We study the lepton forward-backward asymmetry ${\mathcal{A}}_{FB}$ and longitudinal ${K}^{*}$ polarization ${F}_{L}$, as well an observable ${P}_{2}$ derived from them, in rare decays $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, where ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ is either ${e}^{+}{e}^{\ensuremath{-}}$ or ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, using full sample of 471 million...
We study the processes $e^+ e^-\to K_S^0 K_L^0 \gamma$, $K_S^0 \pi^+\pi^-\gamma$, and K^+K^-\gamma$, where photon is radiated from initial state, providing cross section measurements for hadronic states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ data collected with BaBar detector at SLAC. observe $\phi(1020)$ resonance in K_L^0$ final state measure product its electronic width branching fraction about 3% uncertainty. present measurement $ energy range...
We study the rare B meson decays B±,0→J/ψK+K−K±,0, B±,0→J/ψϕK±,0, and search for B0→J/ψϕ, using 469×106 B¯B events collected at Υ(4S) resonance with BABAR detector PEP-II e+e− asymmetric energy collider. present new measurements of branching fractions a J/ψϕ mass distribution in charmonium-like states. In addition, we decay B0→J/ψϕ find no evidence signal.1 MoreReceived 31 July 2014DOI:https://doi.org/10.1103/PhysRevD.91.012003© 2015 American Physical Society
We present a search for neutral, long-lived particle L that is produced in e+ e- collisions and decays at significant distance from the interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an data sample with luminosity 489.1 fb(-1) collected by BABAR detector ϒ(4S), ϒ(3S), ϒ(2S) resonances just below ϒ(4S). Fitting two-track mass distribution signal peak, we do not observe signal, set 90% confidence level upper limits on product production...
Based on a sample of 500 million ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ events recorded by the BABAR detector at c.m. energies close to 10.6 GeV, we report study decay ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$. We measure ratio branching fractions,...
We present Dalitz plot analyses for the decays of $B$ mesons to ${D}^{\ensuremath{-}}{D}^{0}{K}^{+}$ and ${\overline{D}}^{0}{D}^{0}{K}^{+}$. report observation ${D}_{s1}^{*}(2700{)}^{+}$ resonance in these two channels obtain measurements mass $M({D}_{s1}^{*}(2700{)}^{+})={2699}_{\ensuremath{-}7}^{+14}\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ width $\mathrm{\ensuremath{\Gamma}}({D}_{s1}^{*}(2700{)}^{+})={127}_{\ensuremath{-}19}^{+24}\text{ }\mathrm{MeV}$, including statistical systematic...
We report on a search for eleven lepton-number violating processes B+→X−ℓ+ℓ'+ with X−=K−, π−, ρ−, K*−, or D− and ℓ+/ℓ'+=e+ μ+, using sample of 471±3 million B¯B events collected the BABAR detector at PEP-II e+e− collider SLAC National Accelerator Laboratory. find no evidence any these modes place 90% confidence level upper limits their branching fractions in range (1.5–26)×10−7.Received 5 November 2013DOI:https://doi.org/10.1103/PhysRevD.89.011102© 2014 American Physical Society
We measure the mass difference, \Delta m_0, between D*(2010)+ and D0 natural line width, \Gamma, of transition -> pi+. The data were recorded with BABAR detector at center-of-mass energies near Upsilon(4S) resonance, correspond to an integrated luminosity approximately 477 1/fb. is reconstructed in decay modes K- pi+ pi- For mode we obtain Gamma = (83.4 +- 1.7 1.5) keV m_0 (145 425.6 0.6 1.8) keV, where quoted errors are statistical systematic, respectively. \Gamma (83.2 1.5 2.6) 426.6 0.5...
We study the processes γγ→K+K−η and γγ→K+K−π0 using a data sample of 519 fb−1 recorded with BABAR detector operating at SLAC PEP-II asymmetric-energy e+e− collider center-of-mass energies near Υ(nS) (n=2,3,4) resonances. observe ηc→K+K−π0 ηc→K+K−η decays, measure their relative branching fraction, perform Dalitz plot analysis for each decay. K∗0(1430)→Kη decay its fraction to Kπ mode be R(K∗0(1430))=B(K∗0(1430)→Kη)B(K∗0(1430)→Kπ)=0.092±0.025+0.010−0.025. The results correspond first...
We present measurements of Collins asymmetries in the inclusive process $e^+e^- \rightarrow h_1 h_2 X$, $h_1h_2=KK,\, K\pi,\, \pi\pi$, at center-of-mass energy 10.6 GeV, using a data sample 468 fb$^{-1}$ collected by BaBar experiment PEP-II $B$ factory SLAC National Accelerator Center. Considering hadrons opposite thrust hemispheres hadronic events, we observe clear azimuthal ratio unlike- to like-sign, and all charged $h_1 h_2$ pairs, which increase with hadron energies. The $K\pi$ are...
We present results of a search for $CP$ violation in ${B}^{0}\mathrm{\text{\ensuremath{-}}}\text{ }{\overline{B}}^{0}$ mixing with the BABAR detector. select sample ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}X{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ decays partial reconstruction method and use kaon tagging to assess flavor other $B$ meson event. determine violating asymmetry...
The $e^+e^-\to K^+K^-$ cross section and charged-kaon electromagnetic form factor are measured in the $e^+e^-$ center-of-mass energy range ($E$) from 2.6 to 8.0 GeV using initial-state radiation technique with an undetected photon. study is performed 469 fb$^{-1}$ of data collected BABAR detector at PEP-II collider energies near 10.6 GeV. found decrease faster than $1/E^2$, approaches asymptotic QCD prediction. Production $K^+K^-$ final state through $J/\psi$ $\psi(2S)$ intermediate states...
We search for the decay Y(1S) -> gamma A0, A0 gg or ss-bar, where is pseudoscalar light Higgs boson predicted by next-to-minimal supersymmetric standard model. use a sample of (17.6 +- 0.3)x 10^6 mesons produced in BaBar experiment via e+e- Y(2S) pi+pi-Y(1S). see no significant signal and set 90%-confidence-level upper limits on product branching fraction B(Y(1S) A0) x B(A0 ss-bar) ranging from 10^-6 to 10^-2 masses range 0.5 9.0GeV/c^2.
We measure the mass difference, $\ensuremath{\Delta}{m}_{0}$, between ${D}^{*}(2010{)}^{+}$ and ${D}^{0}$ natural linewidth, $\ensuremath{\Gamma}$, of transition ${D}^{*}(2010{)}^{+}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{+}$. The data were recorded with BABAR detector at center-of-mass energies near $\ensuremath{\Upsilon}(4S)$ resonance, correspond to an integrated luminosity approximately $477\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. is reconstructed in decay modes...