A5035388118- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Particle Detector Development and Performance
- Cosmology and Gravitation Theories
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- Noncommutative and Quantum Gravity Theories
- Particle accelerators and beam dynamics
- Scientific Computing and Data Management
- Physics of Superconductivity and Magnetism
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
- Radiation Therapy and Dosimetry
- Radioactive Decay and Measurement Techniques
- Magnetic confinement fusion research
- Electron and X-Ray Spectroscopy Techniques
- Relativity and Gravitational Theory
- International Science and Diplomacy
Paul Scherrer Institute
2016-2025
University of Zurich
2018-2025
University of California, Santa Cruz
2024
European Organization for Nuclear Research
2014-2023
Institut Català de Ciències del Clima
2023
Universitat de Barcelona
2023
Université Savoie Mont Blanc
2022
Laboratoire d'Annecy-le-Vieux de Physique Théorique
2022
Centre National de la Recherche Scientifique
2022
Institute for High Energy Physics
2022
We review the present status of Standard Model calculation anomalous magnetic moment muon. This is performed in a perturbative expansion fine-structure constant $\alpha$ and broken down into pure QED, electroweak, hadronic contributions. The QED contribution by far largest has been evaluated up to including $\mathcal{O}(\alpha^5)$ with negligible numerical uncertainty. electroweak suppressed $(m_\mu/M_W)^2$ only shows at level seventh significant digit. It two loops known better than one...
The LHC has observed, so far, 3 deviations from the Standard Model (SM) predictions in flavor observables: LHCb reported anomalies B→K*μ(+)μ(-) and R(K)=B→Kμ(+)μ(-)/B→Ke(+)e(-), while CMS found an excess h→μτ. We show, for first time, how these SM can be explained within a single well-motivated model: two-Higgs-doublet model with gauged L(μ)-L(τ) symmetry. find that, despite constraints τ→μμμ B(s)-B¯(s) mixing, one explain h→μτ, R(K) simultaneously, obtaining interesting correlations among...
We study the impact of an additional $U(1{)}^{\ensuremath{'}}$ gauge symmetry with flavor-dependent charges for quarks and leptons on LHC flavor anomalies observed in $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, $R(K)=B\ensuremath{\rightarrow}K{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}/B\ensuremath{\rightarrow}K{e}^{+}{e}^{\ensuremath{-}}$, $h\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\tau}$. In its minimal version two...
We perform an extensive study of flavor observables in a 2HDM with generic Yukawa structure (the decoupling limit the MSSM). examine effects physics and constrain model both from tree-level processes loop-observables. The free parameters are heavy Higgs mass, tan(\beta) "non-holomorphic" couplings \epsilon^f_ij (f=u,d,\ell). In our analysis we elements various ways: first step give order magnitude constraints on 't Hooft's naturalness criterion. Then type-III FCNC (B_s,d->\mu^+\mu^-,...
The LHCb Collaboration reported anomalies in $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, ${B}_{s}\ensuremath{\rightarrow}\ensuremath{\phi}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, and $R(K)=B\ensuremath{\rightarrow}\phantom{\rule{0ex}{0ex}}K{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}/B\ensuremath{\rightarrow}K{e}^{+}{e}^{\ensuremath{-}}$. Furthermore, BABAR, BELLE, Collaborations found hints for the violation of...
Over the past years, experiments accumulated intriguing hints for new physics (NP) in flavor observables, namely anomalous magnetic moment of muon ($a_\mu$), $R(D^{(*)})={\rm Br}(B\to D^{(*)}\tau\nu)/{\rm D^{(*)}\ell\nu)$ and $b\to s\mu^+\mu^-$ transitions, which are all at $3-4\,\sigma$ level. In this article we point out that one can explain $R(D^{(*)})$ anomaly using two scalar leptoquarks (LQs) with same mass coupling to fermions related via a discrete symmetry: an $SU(2)$ singlet...
We present the physics program of Belle II experiment, located on intensity frontier SuperKEKB $e^+e^-$ collider. collected its first collisions in 2018, and is expected to operate for next decade. It anticipated collect 50/ab collision data over lifetime. This book outcome a joint effort collaborators theorists through theory interface platform (B2TiP), an that commenced 2014. The aim B2TiP was elucidate potential impacts program, which includes wide scope topics: B physics, charm, tau,...
Lepton number as a fourth color is the intriguing theoretical idea of famous Pati-Salam (PS) model. While in conventional PS models, symmetry breaking scale and mass resulting vector leptoquark are stringently constrained by K_{L}→μe K→πμe, can be lowered to few TeV adding vectorlike fermions. Furthermore, this case, hints for lepton flavor universality violation b→sμ^{+}μ^{-} b→cτν processes addressed. Such setup naturally achieved implementing gauge group five-dimensional Randall-Sundrum...
In the Standard Model (SM), rare transitions where a bottom quark decays into strange and pair of light leptons exhibit potential sensitivity to physics beyond SM. addition, SM embeds Lepton Flavour Universality (LFU), leading almost identical probabilities for muon electron modes. The LHCb collaboration discovered set deviations from expectations in muons also ratios assessing LFU. Other experiments (Belle, ATLAS, CMS) found consistent measurements, albeit with large error bars. We perform...
Recently, the BABAR Collaboration reported first evidence for new physics in $B\ensuremath{\rightarrow}D\ensuremath{\tau}\ensuremath{\nu}$ and $B\ensuremath{\rightarrow}{D}^{*}\ensuremath{\tau}\ensuremath{\nu}$. Combining both processes, significance is $3.4\ensuremath{\sigma}$. This result cannot be explained a two Higgs doublet model of type II. Furthermore, CKMfitter Group finds $2.9\ensuremath{\sigma}$ discrepancy between Standard Model prediction...
With the long-standing tension between experiment and Standard-Model (SM) prediction in anomalous magnetic moment of muon, $a_\mu=(g-2)_\mu/2$, at level 3-4$\sigma$, it is natural to ask if there could be a sizable effect electric dipole (EDM) $d_\mu$ as well. In this context has often been argued that UV complete models electron EDM, which very precisely measured, excludes large $d_\mu$. However, recently observed 2.5$\sigma$ $a_e=(g-2)_e/2$, confirmed, requires muon sectors effectively...
BABAR, Belle, and LHCb Collaborations report evidence for new physics in B→Dτν B→D^{*}τν of approximately 3.8σ. There is also the long lasting discrepancy about 3σ anomalous magnetic moment muon, branching ratio τ→μνν 1.8σ (2.4σ) above standard model expectation using HFAG (PDG) values. Furthermore, CMS Collaboration finds hints a nonzero decay rate h→μτ. Interestingly, all these observations can be explained by introducing scalars. In this Letter we consider processes within lepton-specific...
In the original version of this manuscript, an error was introduced on pp352. '2.7nb:1.6nb' has been corrected to '2.4nb:1.3nb' in current online and printed version. doi:10.1093/ptep/ptz106.
Lepton number as a fourth color is an intriguing theoretical idea which combined with possible left-right symmetry within the famous Pati-Salam (PS) model. In conventional PS model, spontaneous breaking of gauge group down to SM one can only take place at very high scales (above PeV scale) due stringent bounds from $K_L\to\mu e$ and $K\to\pi\mu induced by resulting vector leptoquarks. this paper, we show that these constraints be avoided once additional vector-like fermions are introduced...
LHCb has reported deviations from the Standard Model in $b\ensuremath{\rightarrow}s{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ transitions for which a new neutral gauge boson is prime candidate an explanation. As this to couple flavor nonuniversal way muons and electrons order explain ${R}_{K}$, it interesting examine possibility that also lepton violated, especially light of CMS excess...
Hadronic vacuum polarization (HVP) is not only a critical part of the standard model (SM) prediction for anomalous magnetic moment muon (g-2)_{μ}, but also crucial ingredient global fits to electroweak (EW) precision observables due its contribution running fine-structure constant encoded in Δα_{had}^{(5)}. We find that with modern EW data, including measurement Higgs mass, fit alone provides competitive, independent determination Δα_{had}^{(5)}|_{EW}=270.2(3.0)×10^{-4}. This value actually...
In recent years experiments revealed intriguing hints for new physics (NP) in $B$ decays involving $b\ensuremath{\rightarrow}c\ensuremath{\tau}\ensuremath{\nu}$ and $b\ensuremath{\rightarrow}s{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ transitions at the $4\ensuremath{\sigma}$ $5\ensuremath{\sigma}$ level, respectively. addition, there are slight disagreements $b\ensuremath{\rightarrow}u\ensuremath{\tau}\ensuremath{\nu}$...
We perform a model-independent global fit to $$b\rightarrow s\ell ^+\ell ^-$$ observables confirm existing New Physics (NP) patterns (or scenarios) and identify new ones emerging from the inclusion of updated LHCb Belle measurements $$R_K$$ $$R_{K^*}$$, respectively. Our analysis, updating Refs. Capdevila et al. (J Virto JHEP 1801:093, 2018) Algueró Matias Phys Rev D 99(7):075017, 2019) including these data, suggests presence right-handed couplings encoded in Wilson coefficients...
In recent years, experiments revealed intriguing hints for new physics (NP) in semi-leptonic B decays. Both charged current processes, involving b → cτν transitions, and the neutral currents sℓ +ℓ −, a preference NP compared to standard model (SM) of more that 3σ 5σ was found, respectively. addition, there is long-standing tension between theory prediction measurement anomalous magnetic moment (AMM) muon (aμ) than 3σ. Since all these observables are related violation lepton flavor...
Precision tests of first-row unitarity the Cabibbo-Kobayashi-Maskawa matrix currently display two intriguing tensions, both at $3\sigma$ level. First, combining determinations $V_{ud}$ from superallowed $\beta$ decays with $V_{us}$ kaon suggests a deficit in relation. At same time, tension similar significance has emerged between $K_{\ell 2}$ and 3}$ decays. In this Letter, we point out that measurement $K_{\mu3}/K_{\mu branching fraction level $0.2\%$ would have considerable impact on...
We show how to avoid unnecessary and uncontrolled assumptions usually made in the literature about soft $SU(3)$ flavor symmetry breaking determining two-flavor nucleon matrix elements relevant for direct detection of weakly interacting massive particles (WIMPs). Based on $SU(2)$ chiral perturbation theory, we provide expressions proton neutron scalar couplings ${f}_{u}^{p,n}$ ${f}_{d}^{p,n}$ with pion-nucleon $\ensuremath{\sigma}$ term as only free parameter, which should be used analysis...
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...
We study lepton flavor observables in the Standard Model (SM) extended with all dimension-6 operators which are invariant under SM gauge group. calculate complete one-loop predictions to radiative decays μ → eγ, τ μγ and eγ as well closely related anomalous magnetic moments electric dipole of charged leptons, taking into account can generate violation. Also 3-body violating ± + −, e ∓ ±, − Z 0 $ \ell_i^{+}\ell_j^{-} considered, tree-level contributions.
The basic features of quark and lepton mass matrices can be successfully explained by natural minima a generic potential with dynamical Yukawa fields invariant under the $[\mathrm{SU(3)}]^5\times \mathcal{O}(3)$ flavor symmetry. If this symmetry is gauged, in order to avoid potentially dangerous Goldstone bosons, small perturbations are added exactly fit observed pattern fermion masses, spectrum massive gauge bosons naturally explain hints for new physics $b\to s \ell^+\ell^-$ transitions,...