S. Akar

ORCID: 0000-0003-0288-9694
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About
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Research Areas
  • Particle physics theoretical and experimental studies
  • Quantum Chromodynamics and Particle Interactions
  • High-Energy Particle Collisions Research
  • Neutrino Physics Research
  • Particle Detector Development and Performance
  • Dark Matter and Cosmic Phenomena
  • Computational Physics and Python Applications
  • Black Holes and Theoretical Physics
  • Particle Accelerators and Free-Electron Lasers
  • Medical Imaging Techniques and Applications
  • Atomic and Subatomic Physics Research
  • Superconducting Materials and Applications
  • Nuclear physics research studies
  • Stochastic processes and statistical mechanics
  • Cosmology and Gravitation Theories
  • Advanced Data Storage Technologies
  • International Science and Diplomacy
  • Distributed and Parallel Computing Systems
  • Radiation Detection and Scintillator Technologies
  • Advanced NMR Techniques and Applications
  • Markov Chains and Monte Carlo Methods
  • Radiation Therapy and Dosimetry
  • Particle accelerators and beam dynamics
  • Cold Atom Physics and Bose-Einstein Condensates
  • Pulsars and Gravitational Waves Research

University of Cincinnati
2017-2025

Institut National de Physique Nucléaire et de Physique des Particules
2011-2025

Université Clermont Auvergne
2025

Clermont Université
2025

Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2023-2024

University of Maryland, College Park
2023

Université Paris Cité
2012-2022

Centre National de la Recherche Scientifique
2012-2022

Sorbonne Université
2012-2022

Laboratoire de Physique Nucléaire et de Hautes Énergies
2013-2022

Observations of exotic structures in the J/ψp channel, which we refer to as charmonium-pentaquark states, Λ0b→J/ψK−p decays are presented. The data sample corresponds an integrated luminosity 3 fb−1 acquired with LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis three-body final state reproduces two-body mass angular distributions. To obtain a satisfactory fit seen spectrum, it is necessary include two Breit-Wigner amplitudes that each describe resonant state. significance...

10.1103/physrevlett.115.072001 article EN cc-by Physical Review Letters 2015-08-12

A measurement of the ratio branching fractions $B^{+}\rightarrow K^{+}\mu^{+}\mu^{-}$ and K^{+}e^{+}e^{-}$ decays is presented using proton-proton collision data, corresponding to an integrated luminosity 3.0 fb$^{-1}$, recorded with LHCb experiment at center-of-mass energies 7 8 $\mathrm{\,Te\kern -0.1em V}$. The value for dilepton invariant mass squared range $1<q^{2}<6\mathrm{\,Ge\kern V^2\!/}c^4$ measured be $0.745^{+0.090}_{-0.074}\mathrm{\,(stat)}\,\pm0.036\mathrm{\,(syst)}$. This most...

10.1103/physrevlett.113.151601 article EN cc-by Physical Review Letters 2014-10-06

The branching fraction ratio R(D^{*})≡B(B[over ¯]^{0}→D^{*+}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]^{0}→D^{*+}μ^{-}ν[over ¯]_{μ}) is measured using a sample of proton-proton collision data corresponding to 3.0 fb^{-1} integrated luminosity recorded by the LHCb experiment during 2011 and 2012. tau lepton identified in decay mode τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}. semitauonic sensitive contributions from non-standard-model particles that preferentially couple third generation fermions, particular,...

10.1103/physrevlett.115.111803 article EN cc-by Physical Review Letters 2015-09-09

A narrow pentaquark state, P_{c}(4312)^{+}, decaying to J/ψp, is discovered with a statistical significance of 7.3σ in data sample Λ_{b}^{0}→J/ψpK^{-} decays, which an order magnitude larger than that previously analyzed by the LHCb Collaboration. The P_{c}(4450)^{+} structure formerly reported confirmed and observed consist two overlapping peaks, P_{c}(4440)^{+} P_{c}(4457)^{+}, where this two-peak interpretation 5.4σ. proximity Σ_{c}^{+}D[over ¯]^{0} ¯]^{*0} thresholds peaks suggests they...

10.1103/physrevlett.122.222001 article EN cc-by Physical Review Letters 2019-06-05

A test of lepton universality, performed by measuring the ratio branching fractions $B^{0} \rightarrow K^{*0}\mu^{+}\mu^{-}$ and K^{*0}e^{+}e^{-}$ decays, $R_{K^{*0}}$, is presented. The $K^{*0}$ meson reconstructed in final state $K^{+}\pi^{-}$, which required to have an invariant mass within 100$\mathrm{\,MeV}c^2$ known $K^{*}(892)^{0}$ mass. analysis using proton-proton collision data, corresponding integrated luminosity about 3$\mathrm{\,fb}^{-1}$, collected LHCb experiment at...

10.1007/jhep08(2017)055 article EN cc-by Journal of High Energy Physics 2017-08-01

The $\Xi_c^+ K^-$ mass spectrum is studied with a sample of $pp$ collision data corresponding to an integrated luminosity 3.3 fb$^{-1}$, collected by the LHCb experiment. $\Xi_c^+$ reconstructed in decay mode $p K^- \pi^+$. Five new, narrow excited $\Omega_c^0$ states are observed: $\Omega_c(3000)^0$, $\Omega_c(3050)^0$, $\Omega_c(3066)^0$, $\Omega_c(3090)^0$, and $\Omega_c(3119)^0$. Measurements their masses widths reported.

10.1103/physrevlett.118.182001 article EN cc-by Physical Review Letters 2017-05-02

Abstract Conventional, hadronic matter consists of baryons and mesons made three quarks a quark–antiquark pair, respectively 1,2 . Here, we report the observation state containing four in Large Hadron Collider beauty experiment. This so-called tetraquark contains two charm quarks, $$\overline{{{{{u}}}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mrow> <mml:mi>u</mml:mi> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> $$\overline{{{{{d}}}}}$$...

10.1038/s41567-022-01614-y article EN cc-by Nature Physics 2022-06-16

The LHCb Upgrade II will fully exploit the flavour-physics opportunities of HL-LHC, and study additional physics topics that take advantage forward acceptance spectrometer. I begin operation in 2020. Consolidation occur, modest enhancements detector be installed, Long Shutdown 3 LHC (2025) these are discussed here. main installed long shutdown 4 (2030) build on strengths current experiment I. It operate at a luminosity up to $ 2 \times 10^{34} \rm cm^{-2}s^{-1}$, ten times detector. New...

10.48550/arxiv.1808.08865 preprint EN cc-by arXiv (Cornell University) 2018-01-01

A search for charge-parity (CP) violation in D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays is reported, using pp collision data corresponding to an integrated luminosity of 5.9 fb^{-1} collected at a center-of-mass energy 13 TeV with the LHCb detector. The flavor charm meson inferred from charge pion D^{*}(2010)^{+}→D^{0}π^{+} or muon B[over ¯]→D^{0}μ^{-}ν[over ¯]_{μ}X decays. difference between CP asymmetries measured be ΔA_{CP}=[-18.2±3.2(stat)±0.9(syst)]×10^{-4} π-tagged...

10.1103/physrevlett.122.211803 article EN cc-by Physical Review Letters 2019-05-29

A bstract search for $$ {B}_s^0\to {\overline{D}}^0{f}_0(980) <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>B</mml:mi><mml:mi>s</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:mo>→</mml:mo><mml:msup><mml:mover><mml:mi>D</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mn>0</mml:mn></mml:msup><mml:msub><mml:mi>f</mml:mi><mml:mn>0</mml:mn></mml:msub><mml:mfenced><mml:mn>980</mml:mn></mml:mfenced></mml:math> decays is performed using 3 . 0 fb 1− of pp collision data...

10.1007/jhep08(2015)005 article EN cc-by Journal of High Energy Physics 2015-08-01

An angular analysis and a measurement of the differential branching fraction decay B 0 → ϕμ + μ − are presented, using data corresponding to an integrated luminosity 3.0 fb−1 pp collisions recorded by LHCb experiment at $$ \sqrt{s}=7 8 TeV. Measurements reported as function q 2, square dimuon invariant mass results found be consistent with Standard Model. In range 1 < 2 6 GeV2 /c 4, where precise theoretical calculations available, is more than 3σ below Model predictions.

10.1007/jhep09(2015)179 article EN cc-by Journal of High Energy Physics 2015-09-01

The first full amplitude analysis of $B^+\to J/ψϕK^+$ with $J/ψ\toμ^+μ^-$, $ϕ\to K^+K^-$ decays is performed a data sample 3 fb$^{-1}$ $pp$ collision collected at $\sqrt{s}=7$ and $8$ TeV the LHCb detector. cannot be described by model that contains only excited kaon states decaying into $ϕK^+$, four $J/ψϕ$ structures are observed, each significance over $5$ standard deviations. quantum numbers these determined least $4$ lightest has mass consistent with, but width much larger than, previous...

10.1103/physrevlett.118.022003 article EN cc-by Physical Review Letters 2017-01-11

Searches are performed for both prompt-like and long-lived dark photons, $A^{\prime}$, produced in proton-proton collisions at a center-of-mass energy of 13 TeV, using $A^{\prime}\to\mu^+\mu^-$ decays data sample corresponding to an integrated luminosity 1.6 fb$^{-1}$ collected with the LHCb detector. The $A^{\prime}$ search covers mass range from near dimuon threshold up 70 GeV, while is restricted low-mass region $214<m(A^{\prime})<350$ MeV. No evidence signal found, 90% confidence level...

10.1103/physrevlett.120.061801 article EN cc-by Physical Review Letters 2018-02-08

First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis Ξb-→J/ψΛK- decays. The observed consistent with being due to charmonium pentaquark strangeness significance 3.1σ including systematic uncertainties and look-elsewhere effect. Its width are determined be 4458.8±2.9-1.1+4.7MeV 17.3±6.5-5.7+8.0MeV, respectively, where quoted statistical systematic. also two resonances. In addition, narrow excited Ξ- states, Ξ1690- Ξ1820-, seen for first...

10.1016/j.scib.2021.02.030 article EN cc-by Science Bulletin 2021-03-10

Branching fraction and effective lifetime measurements of the rare decay $B^0_s\to\mu^+\mu^-$ searches for decays $B^0\to\mu^+\mu^-$ $B^0_s\to\mu^+\mu^-\gamma$ are reported using proton-proton collision data collected with LHCb detector at centre-of-mass energies $7$ TeV, $8$ TeV $13$ corresponding to a luminosity $9$ fb$^{-1}$. The branching ${\mathcal{B}}(B^0_s\to\mu^+\mu^-)=\left(3.09^{+0.46+0.15}_{-0.43-0.11}\right)\times 10^{-9}$ $\tau(B^0_s\to\mu^+\mu^-)=(2.07\pm 0.29\pm 0.03)$...

10.1103/physrevlett.128.041801 article EN cc-by Physical Review Letters 2022-01-25

The first simultaneous test of muon-electron universality using B^{+}→K^{+}ℓ^{+}ℓ^{-} and B^{0}→K^{*0}ℓ^{+}ℓ^{-} decays is performed, in two ranges the dilepton invariant-mass squared, q^{2}. analysis uses beauty mesons produced proton-proton collisions collected with LHCb detector between 2011 2018, corresponding to an integrated luminosity 9 fb^{-1}. Each four lepton measurements reported either given q^{2} interval or supersedes previous measurements. results are compatible predictions...

10.1103/physrevlett.131.051803 article EN cc-by Physical Review Letters 2023-08-02

Tests of lepton universality in B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} decays where ℓ is either an electron or a muon are presented. The differential branching fractions B^{0}→K_{S}^{0}e^{+}e^{-} B^{+}→K^{*+}e^{+}e^{-} measured intervals the dilepton invariant mass squared. measurements performed using proton-proton collision data recorded by LHCb experiment, corresponding to integrated luminosity 9 fb^{-1} . results consistent with standard model previous tests related decay...

10.1103/physrevlett.128.191802 article EN cc-by Physical Review Letters 2022-05-11

An amplitude analysis of B^{-}→J/ψΛp[over ¯] decays is performed using 4400 signal candidates selected on a data sample pp collisions recorded at center-of-mass energies 7, 8, and 13 TeV with the LHCb detector, corresponding to an integrated luminosity 9 fb^{-1}. A narrow resonance in J/ψΛ system, consistent pentaquark candidate strangeness, observed high significance. The mass width this new state are measured be 4338.2±0.7±0.4 MeV 7.0±1.2±1.3 MeV, where first uncertainty statistical second...

10.1103/physrevlett.131.031901 article EN cc-by Physical Review Letters 2023-07-17

A simultaneous analysis of the B+→K+ℓ+ℓ− and B0→K*0ℓ+ℓ− decays is performed to test muon-electron universality in two ranges square dilepton invariant mass, q2. The measurement uses a sample beauty meson produced proton-proton collisions collected with LHCb detector between 2011 2018, corresponding an integrated luminosity 9 fb−1. sequence multivariate selections strict particle identification requirements produce higher signal purity better statistical sensitivity per unit than previous...

10.1103/physrevd.108.032002 article EN cc-by Physical review. D/Physical review. D. 2023-08-02

A combined amplitude analysis is performed for the decays B^{0}→D[over ¯]^{0}D_{s}^{+}π^{-} and B^{+}→D^{-}D_{s}^{+}π^{+}, which are related by isospin symmetry. The based on data collected LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8, 13 TeV. full sample corresponds to an integrated luminosity 9 fb^{-1}. Two new resonant states with masses 2.908±0.011±0.020 GeV widths 0.136±0.023±0.013 observed, decay D_{s}^{+}π^{+} D_{s}^{+}π^{-} respectively. former state...

10.1103/physrevlett.131.041902 article EN cc-by Physical Review Letters 2023-07-27

The branching fraction $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\tau}}^{+}{\ensuremath{\nu}}_{\ensuremath{\tau}})$ is measured relative to that of the normalization mode ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ using hadronic...

10.1103/physrevd.108.012018 article EN cc-by Physical review. D/Physical review. D. 2023-07-27

The ratios of branching fractions $\mathcal{R}({D}^{*})\ensuremath{\equiv}\mathcal{B}(\overline{B}\ensuremath{\rightarrow}{D}^{*}{\ensuremath{\tau}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}})/\mathcal{B}(\overline{B}\ensuremath{\rightarrow}{D}^{*}{\ensuremath{\mu}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}})$ and...

10.1103/physrevlett.131.111802 article EN cc-by Physical Review Letters 2023-09-13

A full amplitude analysis of $\Lambda_b^0 \to J/\psi p \pi^-$ decays is performed with a data sample acquired the LHCb detector from 7 and 8 TeV $pp$ collisions, corresponding to an integrated luminosity 3 fb$^{-1}$. significantly better description achieved when, in addition previously observed nucleon excitations $N\to p\pi^-$, either $P_c(4380)^+$ $P_c(4450)^+\to p$ states, K^-$ decays, or $Z_c(4200)^-\to state, reported $B^0 K^+ all three, are included models. The support model...

10.1103/physrevlett.117.082003 article EN cc-by Physical Review Letters 2016-08-18

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...

10.48550/arxiv.1812.07638 preprint EN other-oa arXiv (Cornell University) 2018-01-01
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