X. Cid Vidal
A5107749023- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Distributed and Parallel Computing Systems
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Stochastic processes and statistical mechanics
- Cosmology and Gravitation Theories
- International Science and Diplomacy
- Mathematics, Computing, and Information Processing
- Simulation Techniques and Applications
- Astrophysics and Cosmic Phenomena
- Particle accelerators and beam dynamics
- Advanced NMR Techniques and Applications
- Markov Chains and Monte Carlo Methods
- Experimental and Theoretical Physics Studies
Universidade de Santiago de Compostela
2016-2025
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2015-2024
Universitat de València
2023
Instituto de Física Corpuscular
2023
Central China Normal University
2014-2023
Tsinghua University
2020-2023
Universitat Ramon Llull
2023
Istituto Nazionale di Fisica Nucleare
2004-2022
University of Cambridge
2021
University of Glasgow
2011-2021
This paper presents the design of LHCb trigger and its performance on data taken at LHC in 2011. A principal goal is to perform flavour physics measurements, designed distinguish charm beauty decays from light quark background. Using a combination lepton identification measurements particles' transverse momenta selects particles originating hadrons, which typically fly finite distance before decaying. The reduces roughly 11 MHz bunch-bunch crossings that contain least one inelastic pp...
The production of J/psi mesons in proton-proton collisions at sqrt(s)=7 TeV is studied with the LHCb detector LHC. differential cross-section for prompt measured as a function transverse momentum pT and rapidity y fiducial region 0<pT<14 GeV/c 2.0<y<4.5. fraction from b-hadron decays are also same ranges. analysis based on data sample corresponding to an integrated luminosity 5.2pb-1. cross-sections over 10.52 +/- 0.04 1.40 +1.64/-2.20 mub 1.14 0.01 0.16 decays, where first uncertainty...
Abstract With the establishment and maturation of experimental programs searching for new physics with sizeable couplings at LHC, there is an increasing interest in broader particle astrophysics community exploring light feebly-interacting particles as a paradigm complementary to New Physics sector TeV scale beyond. FIPs 2020 has been first workshop fully dedicated was held virtually from 31 August 4 September 2020. The gathered together experts collider, beam dump, fixed target experiments,...
Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at weak scale. When produced experiments such as Large Hadron Collider (LHC) CERN, these long-lived (LLPs) decay far from interaction vertex of primary proton-proton collision. Such LLP signatures distinct those promptly decaying targeted by majority searches for new physics LHC, often requiring customized techniques identify, example, significantly displaced vertices, tracks with...
Abstract Using 34.7 pb −1 of data collected with the LHCb detector, inclusive production X (3872) meson in pp collisions at $\sqrt{s}=7\mbox{~TeV}$ is observed for first time. Candidates are selected (3872)→ J / ψπ + π − decay mode, and used to measure "Equation missing" where σ ( → (3872)+anything) cross section mesons rapidity range 2.5–4.5 transverse momentum 5–20 GeV/ c . In addition masses both ψ (2 S ) mesons, reconstructed final state, measured be $$m_{X(3872)} = 3871.95 \pm0.48 \...
Measurements of $b$ hadron production ratios in proton-proton collisions at a centre-of-mass energy 7 TeV with an integrated luminosity 3 pb$^{-1}$ are presented. We study the strange $B$ meson to light $f_s/(f_u+f_d)$ and $\Lambda_b^0$ baryon $f_{\Lambda_b}/(f_u+f_d)$ as function charmed hadron-muon pair transverse momentum $p_T$ pseudorapidity $\eta$, for between 0 14 GeV $\eta$ 2 5. find that is consistent being independent $p_{\rm T}$ we determine = 0.134$\pm$ 0.004 $^{+0.011}_{-0.010}$,...
The production of $J/\psi$ pairs in proton-proton collisions at a centre-of-mass energy 7 TeV has been observed using an integrated luminosity $37.5 pb^{-1}$ collected with the LHCb detector. cross-section for both \jpsi rapidity range $2<y^{J/\psi}<4.5$ and transverse momentum $p_{T}^{J/\psi}<10 GeV/c$ is $$ \sigma^{J/\psi J/\psi} = 5.1\pm1.0\pm1.1 nb,$$ where first uncertainty statistical second systematic.
We present a measurement of the time-dependent $CP$-violating asymmetry in ${B}_{s}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}$ decays, using data collected with LHCb detector at LHC. The decay time distribution is characterized by widths ${\ensuremath{\Gamma}}_{H}$ and ${\ensuremath{\Gamma}}_{L}$ heavy light mass eigenstates, respectively, ${B}_{s}^{0}\ensuremath{-}{\overline{B}}_{s}^{0}$ system phase ${\ensuremath{\phi}}_{s}$. In sample about 8500 events isolated from...
The production of $J/\psi$ mesons accompanied by open charm, and pairs charm hadrons are observed in pp collisions at a centre-of-mass energy 7 TeV using an integrated luminosity $355pb^{-1}$ collected with the LHCb detector. Model independent measurements absolute cross-sections given together ratios to measured cross-sections. properties these events studied compared theoretical predictions.
The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for light vector mediator this dark force, $\mathrm{U}$ boson, with KLOE detector at DA$\Phi$NE $\mathrm{e}^{+}\mathrm{e}^{-}$ collider. Using an integrated luminosity 1.54 fb$^{-1}$, we studied process $\mathrm{e}^{+}\mathrm{e}^{-} \to \mathrm{U}\gamma$, $\mathrm{U} \mathrm{e}^{+}\mathrm{e}^{-}$, using...
The performance of the muon identification in LHCb is extracted from data using muons and hadrons produced J/ψ → μ+μ−, Λ0 pπ− D⋆+→π+D0(K−π+) decays. procedure based on pattern hits chambers. A momentum dependent binary requirement used to reduce probability be misidentified as level 1%, keeping efficiency range 95-98%. As further refinement, a likelihood built for non-muon hypotheses. Adding this that provides total at 93%, hadron misidentification probabilities are below 0.6%.
We have searched for a light vector boson U, the possible carrier of "dark force", with KLOE detector at DAΦNE e+e− collider, motivated by astrophysical evidence presence dark matter in Universe. Using collisions collected an integrated luminosity 239.3 pb−1, we look dimuon mass peak reaction e+e−→μ+μ−γ, corresponding to decay U→μ+μ−. find no U signal. set 90% CL upper limit mixing parameter squared between photon and 1.6×10−5 8.6×10−7 region 520<mU<980 MeV.
Abstract This document presents the physics case and ancillary studies for proposed CODEX-b long-lived particle (LLP) detector, as well a smaller proof-of-concept demonstrator CODEX- $$\beta $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>β</mml:mi> </mml:math> , to be operated during Run 3 of LHC. Our development synthesizes ‘top-down’ ‘bottom-up’ theoretical approaches, providing detailed survey both minimal complete models featuring LLPs. Several these have not been...
The recent interest in a light gauge boson the framework of an extra U(1) symmetry motivates searches mass range below 1 GeV. We present search for such particle, dark photon, e+e−→Uγ, U→π+π− based on 28 million e+e−→π+π−γ events collected at DAΦNE by KLOE experiment. π+ π− production initial-state radiation compensates loss sensitivity previous U→e+e−, μ+μ− due to small branching ratios ρ–ω resonance region. found no evidence signal and set limit 90% CL mixing strength between photon ε2, U...
This report comprises the outcome of five working groups that have studied physics potential high-luminosity phase LHC (HL-LHC) and perspectives for a possible future high-energy (HE-LHC).The covered broad range topics: Standard Model measurements, studies properties ofthe Higgs boson, searches phenomena beyond Model, flavor heavy quarks leptonsand QCD matter at high density temperature.The work is prepared as an input to ongoing process updating European Strategy Particle Physics,a will be...
A bstract We assess the impact of searches at flavor factories for new neutral resonances that couple to both photons and gluons. These are well motivated by “heavy axion” solutions strong CP problem frameworks addressing Dark Matter Higgs hierarchy problem. use LHCb public diphoton data around B s mass derive current best limit on these masses between 4.9 6.3 GeV. estimate a future dedicated search would test an axion decay constant O (TeV) in few-to-tens GeV, being fully complementary low...
Received 13 March 2012DOI:https://doi.org/10.1103/PhysRevLett.108.129903This article is available under the terms of Creative Commons Attribution 3.0 License. Further distribution this work must maintain attribution to author(s) and published article’s title, journal citation, DOI.© 2012 American Physical Society
The angular distributions and the partial branching fraction of decay $B^{0} \rightarrow K^{*0} \mu^+ \mu^-$ are studied using an integrated luminosity $0.37\,fb^{-1}$ data collected with LHCb detector. forward-backward asymmetry muons, $A_{\mathrm{FB}}$, longitudinal polarisation, $F_{\mathrm{L}}$, fraction, $\mathrm{d}{\mathcal B}/\mathrm{d}q^{2}$, determined as a function dimuon invariant mass. measurements in good agreement Standard Model predictions most precise to date. In mass squared...
The decay ${\overline{B}}_{s}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ can be exploited to study $CP$ violation. A detailed understanding of its structure is imperative in order optimize usefulness. An analysis this three-body final state performed using a $1.0\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ sample data produced 7 TeV $pp$ collisions at the LHC and collected by LHCb experiment. modified Dalitz plot both...
Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, hadronic decay Bs -> J/psi f0(980) is observed. This CP eigenstate mode could be used to measure mixing-induced violation B_s system. fit pi+ pi- mass spectrum interfering resonances gives R_{f0/phi} = [Gamma(Bs f0, f0 pi-)]/[Gamma(Bs phi, phi K+K-)] 0.252^{+0.046+0.027}_{-0.032-0.033}, where uncertainties are statistical and systematic, respectively.
Neutral kaon pairs produced in phi decays anti-symmetric entangled state can be exploited to search for violation of CPT symmetry and Lorentz invariance. We present an analysis the CP-violating process phi->K_S K_L->pi+pi-pi+pi- based on 1.7 fb-1 data collected by KLOE experiment at Frascati phi-factory DAFNE. The are used perform a measurement CPT-violating parameters Delta_amu neutral kaons contest Standard Model Extension framework. measured reference frame fixed stars are: Delta_ao =...
A search for the $X(4140)$ state in ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}{K}^{+}$ decays is performed with $0.37\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $pp$ collisions at $\sqrt{s}=7\text{ }\mathrm{TeV}$ collected by LHCb experiment. No evidence this found, $2.4\ensuremath{\sigma}$ disagreement a measurement CDF. An upper limit on its production rate set,...