K. De Bruyn
A5070802353- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Stochastic processes and statistical mechanics
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Distributed and Parallel Computing Systems
- Particle accelerators and beam dynamics
- Wireless Communication Security Techniques
- Cellular Automata and Applications
- International Science and Diplomacy
- Markov Chains and Monte Carlo Methods
- Advanced Data Storage Technologies
- Astrophysics and Cosmic Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
National Institute for Subatomic Physics
2014-2025
University of Groningen
2020-2025
Universitat Ramon Llull
2023
RWTH Aachen University
2023
Universitat de Barcelona
2023
Vrije Universiteit Amsterdam
2023
The University of Melbourne
2023
Maastricht University
2023
European Organization for Nuclear Research
2013-2021
Petersburg Nuclear Physics Institute
2012-2021
We have recently seen new upper bounds for B(s)(0)→μ(+)μ(-), a key decay to search physics beyond the standard model. Furthermore nonvanishing width difference ΔΓ(s) of B(s) system has been measured. show that affects extraction B(s)(0)→μ(+)μ(-) branching ratio and resulting constraints on parameter space give formulas including this effect. Moreover, we point out provides observable, effective lifetime τ(μ(+)μ(-)), which offers theoretically clean probe searches is complementary ratio....
We have just entered an era of precision measurements for $B_s$-decay observables. A characteristic feature the $B_s$-meson system is $B^0_s$--$\bar B^0_s$ mixing, which exhibits a sizable decay width difference. The latter leads to subtle complication extraction branching ratios $B_s$ decays from untagged data samples, leading systematic biases as large O(10%) that depend on dynamics considered decay. point out this effect can only be corrected using information time-dependent analysis and...
Motivated by the success of flavour physics programme carried out over last decade at Large Hadron Collider (LHC), we characterize in detail potential its High-Luminosity and High-Energy upgrades this domain physics. We document extraordinary breadth HL/HE-LHC enabled a putative Upgrade II dedicated experiment LHCb evolution established role ATLAS CMS general purpose experiments. connect to studies top quark, Higgs boson, direct high-$p_T$ searches for new particles force carriers. discuss...
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 production of Upsilon(1S), Upsilon(2S) and Upsilon(3S) mesons in proton-proton collisions at the centre-of-mass energy sqrt(s)=7 TeV is studied with LHCb detector. analysis based on a data sample 25 pb-1 collected Large Hadron Collider. Upsilon are reconstructed decay mode -> mu+ mu- signal yields extracted from fit to invariant mass distributions. differential cross-sections times dimuon branching fractions measured as function transverse momentum pT rapidity y, over range < 15 GeV/c...
The differential cross-section for the inclusive production of ψ(2S) mesons in pp collisions at $\sqrt{s}=7\ \mbox{TeV}$ has been measured with LHCb detector. data sample corresponds to an integrated luminosity 36 pb−1. are reconstructed decay channels ψ(2S)→μ + μ − and ψ(2S)→J/ψπ π −, J/ψ meson decaying into two muons. Results presented both promptly produced those originating from b-hadron decays. In kinematic range p T(ψ(2S))≤16 GeV/c 2<y(ψ(2S))≤4.5 we measure where last uncertainty on...
The interference between the K+ K- S-wave and P-wave amplitudes in B(s)(0) → J/ψK+ decays with pairs region around ϕ(1020) resonance is used to determine variation of difference strong phase these as a function invariant mass. Combined results from our CP asymmetry measurement J/ψϕ decays, we conclude that mass eigenstate almost = +1 lighter faster than -1. This determines sign decay width ΔΓ(s) ≡ Γ(L) - Γ(H) be positive. Our result also resolves ambiguity past measurements violating ϕ(s)...
An analysis of B±→DK± and B±→Dπ± decays is presented where the D meson reconstructed in two-body final states: K±π∓, K+K− π+π−. Using 1.0 fb−1 s=7TeV pp collisions, measurements several observables are made including first observation suppressed mode B±→[π±K∓]DK±. CP violation observed with 5.8σ significance.
The prompt production of charmonium $\chi_{c}$ and $J/\psi$ states is studied in proton-proton collisions at a centre-of-mass energy $\sqrt{s}=7$ TeV the Large Hadron Collider. mesons are identified through their decays $\chi_{c}\rightarrow J/\psi \gamma$ $J/\psi\rightarrow \mu^+\mu^-$ using 36 pb$^{-1}$ data collected by LHCb detector 2010. ratio cross-sections for $J/\psi$, $\sigma (\chi_{c}\rightarrow \gamma)/ \sigma (J/\psi)$, determined as function transverse momentum range $2 <...
The calibration and performance of the opposite-side flavour tagging algorithms used for measurements time-dependent asymmetries at LHCb experiment are described. have been developed using simulated events optimized calibrated with B +→J/ψK +, 0→J/ψK ∗0 0→D ∗− μ + ν decay modes 0.37 fb−1 data collected in pp collisions $\sqrt{s} = 7\mbox{~TeV}$ during 2011 physics run. power is determined channel to be (2.10±0.08±0.24) %, where first uncertainty statistical second systematic.
Based on data corresponding to an integrated luminosity of 0.37 fb^-1 collected by the LHCb experiment in 2011, following ratios branching fractions are measured: B(B0 -> pi+ pi-) / K+pi-) = 0.262 +/- 0.009 0.017, (fs/fd) * B(Bs K+K-) B(B^0 0.316 0.019, ->pi+ K-) 0.074 0.006 0.006, (fd/fs) 0.018 {+ 0.008 - 0.007} 0.009, pi+pi-) 0.050 0.011 0.009} 0.004, B(Lambda_b p 0.86 0.08 0.05, where first uncertainties statistical and second systematic. Using current world average ratio strange light...
The production of J/ψ mesons accompanied by open charm hadrons, and pairs hadrons in pp collisions at a centre-of-mass energy 7 TeV has been reported ref. [1].For all measured cross-sections the inclusion charge conjugate processes was implied, so that e.g.,
The LHCb collaboration has redesigned its trigger to enable the full offline detector reconstruction be performed in real time. Together with real-time alignment and calibration of detector, a software infrastructure make persistent high-level physics objects produced during processing, this redesign enabled widespread deployment analysis Run 2. We describe design 2 reconstruction, present data-driven performance measurements for representative sample LHCb's programme.
Controlling the contributions from doubly Cabibbo-suppressed penguin topologies in decays $B_d^0\to J/\psi K^0_{\text{S}}$ and $B_s^0\to J/\psi\phi$ is mandatory to reach highest possible precision measurement of $B^0_q$-$\bar B^0_q$ ($q=d,s$) mixing phases $\phi_d$ $\phi_s$. The can be determined using a strategy based on $SU(3)$ flavour symmetry QCD. Using latest experimental data, we update our combined analysis K^0_{\text{S}}$, their control channels J/\psi\pi^0$ J/\psi\rho^0$. This...
Experimentally, the phases $\phi_d$ and $\phi_s$ are determined from CP asymmetry measurements in "golden modes" $B_d^0\to J/\psi K_{\mathrm{S}}^0$ $B_s^0\to J/\psi\phi$. At leading order, theoretical interpretation of these is straightforward. However, to reach high precision determinations $\phi_s$, which essential view searches for signs beyond SM physics, corrections next-to-leading order effects need be accounted for. These primarily originate so-called penguin topologies. Using $SU(3)$...
Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is prime importance probing new physics. Here 7421 +/- 105 signal events from dominantly CP-odd final state J/\psi pi+ pi- are selected 1/fb pp collision data collected at sqrt{s} = 7 TeV with LHCb detector. A time-dependent fit to yields a value phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent Standard Model expectation. No evidence direct CP violation found.
A study of mixing and indirect CP violation in D0 mesons through the determination parameters y_CP A_\Gamma\ is presented. The parameter deviation from unity ratio effective lifetimes measured decays to eigenstate K+K- with respect Cabibbo favoured mode K-\pi+. result using data collected by LHCb 2010, corresponding an integrated luminosity 29 pb^-1, = (5.5+/-6.3_{stat}+/-4.1_{syst}) x 10^-3. asymmetry anti-D0 K+K-. (-5.9+/-5.9_{stat}+/-2.1_{syst}) data-driven technique used correct for...
A bstract The production of B ± mesons in proton-proton collisions at $ \sqrt {s} = 7 TeV is studied using 35 pb −1 data collected by the LHCb detector. are reconstructed exclusively → J/ψK mode, with J/ψ μ + − . differential cross-section measured as a function transverse momentum fiducial region 0 < p T 40 GeV / c and rapidity 2 y 4 5. total cross-section, summing up , to be σ ( pp X, 5) 41 1 5 (stat ) 3 (syst μb
Measurements of CP violation in $B^0_d\to J/\psi K_{\rm S}^0$ and $B^0_s\to \phi$ decays play key roles testing the quark-flavour sector Standard Model. The theoretical interpretation corresponding observables is limited by uncertainties from doubly Cabibbo-suppressed penguin topologies. With continuously increasing experimental precision, it mandatory to get a handle on these contributions, which cannot be calculated reliably QCD. In case measurement $\sin2\beta$ S}^0$, $U$-spin-related...
A study of $B_c^+\to K^+K^-\pi^+$ decays is performed for the first time using data corresponding to an integrated luminosity 3.0 $\mathrm{fb}^{-1}$ collected by LHCb experiment in $pp$ collisions at centre-of-mass energies $7$ and $8$ TeV. Evidence decay $B_c^+\to\chi_{c0}(\to K^+K^-)\pi^+$ reported with a significance 4.0 standard deviations, resulting measurement $\frac{\sigma(B_c^+)}{\sigma(B^+)}\times\mathcal{B}(B_c^+\to\chi_{c0}\pi^+)$ be $(9.8^{+3.4}_{-3.0}(\mathrm{stat})\pm...