Flavor Physics at Belle II

• Francesco Tenchini

Room: E.0.11 The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. With this data set, Belle II will be able to measure the Cabibbo-Kobayashi-Maskawa (CKM) matrix, the matrix elements and their phases, with unprecedented precision and explore flavor physics with $B$ and charmed mesons, and $\tau$ leptons. Belle II has also a unique capability to search for low mass dark matter and low mass mediators. We also expect exciting results in quarkonium physics with Belle II. From February to July of this year, the machine has completed a commissioning run, achieved a peak luminosity of $5.5\times 10^{33}$ cm$^{-2}$s$^{-1}$, and Belle II has recorded a data sample of about 0.5 fb$^{-1}$. Regular operations are expected to start in March 2019. In this presentation, we will review the status of the Belle II detector, the results of the commissioning run and the near-term prospects for physics at Belle II.

Anomalies in b->s ll transitions (LHCb)

• Titus Mombächer

Room: E.0.11 The concept of lepton universality, where the muon and tau particles are simply heavier copies of the electron, is a key prediction in the Standard Model (SM). In models beyond the SM, lepton universality can be naturally violated with new physics particles that couple preferentially to the second and third generation leptons. Over the last few years, several hints of lepton universality violation have been seen in both b->c and b->s semileptonic beauty decays. This presentation will review the anomalies in b->s ll transitions and give an outlook for the near future.

Progress in Lattice QCD in the B and D Systems

• Andreas Kronfeld (Fermilab)

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Muon Lepton Flavor Violation

• Angela Papa

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Lepton Flavor Violation

• Lorenzo Calibbi

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Tau/Charm factory

• Simon Eidelmann

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Aligned and Spontaneous Flavor Violation

• Daniel Egana-Ugrinovic (Stony Brook University)

Room: E.0.11 We present a spurion setup called Spontaneous Flavor Violation (SFV) that allows for new physics couplings to quarks that are aligned with the Standard Model Yukawas, but do not necessarily share their hierarchies nor are family universal. We show that SFV naturally arises in theories where the quark family number and CP groups are spontaneously broken at a UV scale. In SFV extensions of the Standard Model, FCNCs are strongly suppressed via the GIM mechanism. We apply this novel flavor Ansatz to a 2HDM, showing that new physics with significant and preferential couplings to first or second generation quarks may be at the electroweak scale. The SFV Ansatz provides strong motivation to search for new physics with generation-specific couplings at colliders.

Flavor Clockwork

• Adrian Carmona

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Effective Field Theories for X Y Z

• Nora Brambilla (Physik Department, TU Munich)

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Exotic and Conventional Quarkonium Physics Prospects at Belle II

• Vladimir Savinov

Room: E.0.11 The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at KEK in Tsukuba, Japan. It aims to record a factor of 50 times more data than its predecessor. The experiment completed a commissioning run in 2018, and began full operation in early 2019. Belle II is uniquely capable of studying the so-called "XYZ" particles: heavy exotic hadrons consisting of more than three quarks. First discovered by Belle, these now number in the dozens, and represent the emergence of a new category within quantum chromodynamics. This talk will present the prospects of Belle II to explore both exotic and conventional quarkonium physics.

CP violation and rare decays in charm decays with LHCb

• Angelo Di Canto

Room: E.0.11 The LHCb experiment has collected large samples of decays of charmed hadrons, and has made measurements of CP violation and mixing parameters with world-leading precision. Recent results on charm physics at LHCb are presented.

CP violation in charm

• Jernej Kamenik

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Semileptonic and leptonic results from 2018 Belle II commissioning data

• Cao Lu

Room: E.0.11 The Belle II experiment, located at the SuperKEKB accelerator complex near Tokyo in Japan, has started its 2019 run to collect collision events at large instantaneous luminosities. In this presentation we show first results from studying missing energy signatures, such as leptonic and semileptonic B meson decays: We report first studies on re-measuring important standard candle processes, such as abundant inclusive B to l X and B to D* l decays, and evaluate the performance of our machine learning based tagging algorithms. In addition, we plan to show first results on control regions and sidebands relevant for re-establishing B to D* and B decays with future Belle II data. We further discuss the potential of Belle II to study the present day anomaly in ratios of charm semileptonic decays with tau-leptons to light leptons, known as R(D) and R(D*)in the literature, with future Belle II data and its potential to measure similar ratios with other hadronic final states.

A four-dimensional form-factor fit to B->D*lnu with hadronic tagging from BaBar

• Biplap Dey

Room: E.0.11 We present results on the first full 4-dimensional angular analysis of B->D*lnu, using the e+e- collision dataset collected by the BaBar experiment at the Y(4S) resonance. One B meson from the Y(4S)->BBbar decay is fully reconstructed in a hadronic decay mode which constrains the kinematics and provides a precise determination of the neutrino momentum vector. We extract the underlying hadronic form-factors employing the model-independent BGL approach and a value for the CKM matrix element Vcb. Last, employing our measured BGL form-factors, we provide new predictions within the Standard Model, for observables related to the the semi-tauonic decay B->D*taunu.

$\Lambda_b \to \Lambda_c\ell\bar\nu$ and $V_{cb}$: keep HQETing

• Zoltan Ligeti

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The flavor of ALP

• Matthias Neubert (JGU Mainz)

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Axion flavour models and ALP production at B factories

• Luca Merlo (Universidad Autonoma de Madrid)

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BSM Physics with Kaon Decays at NA62

• Rainer Wanke

Room: E.0.11 The NA62 experiment at CERN SPS was designed to measure BR(K+ -> pi+ nu nu-bar) with in-flight decays, a novel technique for this channel. NA62 took its first physics data in 2016, reaching sensitivity to the decay at the Standard Model BR. The experiment collected 10 times more statistics in 2017 and a similar amount of data is expected from the 2018 run. The result on K+ -> pi+ nu nu from the full 2016 data set will be presented and prospects for future improvements will be discussed. A large sample of charged kaon decays into final states with multiple charged particles was also collected in 2016-2018. The sensitivity to a number of Lepton Flavour and Lepton Number violating K+ decays provided by this data set is an order of magnitude beyond the current state of the art. Results of the search for these processes with a partial NA62 data sample are available for presentation.

Radiative decays at LHCb

• Biplap Dey

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Flavour Physics with High-pT Leptons

• Admir Greljo (CERN)

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More tests of B-decay discrepancies

• Diego Guadagnoli (TUM)

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Theory progress in inclusive b->qll decays

• Tobias Huber

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Power corrections to the inclusive b > s,d ll decays

• Tobias Hurth

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Charm-loop effect in B->K(*)ll decays beyond leading twist

• Nico Gubernari (technische universität münchen)

Room: E.0.11 We revisit soft gluon contributions to the "charm loop" effect in rare $B\to K^{(*)}ll$ decays, which is a large systematic uncertainty in the interpretation of the $b$-anomalies. Since these contributions are dominated by long-distance effects and are resistant to factorization attempts, we employ the method of light-cone sum rules to compute the relevant hadronic matrix elements. Our calculation extends previous works by considering the full set of the three-particle $B$-meson distribution amplitudes. We provide first numerical results, and discuss qualitatively their impact on the extraction of the Wilson coefficient $C_9$.

Vcb

• Christoph Schwanda

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CP violation in beauty decays with LHCb

• Mirco Dorigo

Room: E.0.11 Precision measurements of CP violating observables in b hadron decays are powerful probes to search for physics effects beyond the Standard Model. The most recent results on CP violation in the decay, mixing and interference of b hadrons obtained by the LHCb Collaboration will be presented, with particular focus on results obtained exploiting the data collected during the Run 2 of LHC. These results represent the world's best constraints, some of which are world-first measurements, of the CP violating phase phi_s.

High-pT Signatures in Vector-Leptoquark Models

• Michael Baker (University of Zurich)

Room: E.0.11 We present a detailed analysis of the collider signatures of TeV-scale massive vector bosons motivated by the hints of lepton flavour non-universality observed in $B$-meson decays. We analyse three representations that necessarily appear together in a large class of ultraviolet-complete models: a colour-singlet ($Z'$), a colour-triplet (the $U_1$ leptoquark), and a colour octet ($G'$). Under general assumptions for the interactions of these exotic states with Standard Model fields, including in particular possible right-handed and flavour off-diagonal couplings or the $U_1$, we derive a series of stringent bounds on masses and couplings that constrain a wide range of explicit new-physics models.

Anomalies in semileptonic B decays (LHCb)

• Annarita Buonaura

Room: E.0.11 Rare decays are powerful probes for Physics beyond the Standard Model (SM), as new particles can have a large impact on physics observables. Recent results on lepton universality tests and measurements of branching fractions and angular distributions of rare b->sll decays have shown tensions with the SM predictions. A review of the latest lepton universality tests in semileptonic b →clν transitions is reported.

New Physics in b → c τ ν: From R(D), R(D*) to Polarisation Observables, B_c → τ ν, and Λ_b → Λ_c τ ν

• Monika Blanke (Karlsruhe Institute of Technology)

Room: E.0.11 In this talk I review the status of new physics in b→cτν transitions in the EFT framework of dimension-six operators, including the very recent Belle results. The fit results, including the recent measurement of FL(D*), are presented for all one- and two-dimensional scenarios resulting from the tree level exchange of a single new particle. Particular emphasis is put on the constraint from the Bc→τν decay rate. I introduce a sum rule for the branching ratios of B→Dτν, B→D*τν and Λb→Λc τν which holds for any NP contribution to the Wilson coefficients and predicts an enhancement of the latter decay w.r.t. the Standard Model. I also discuss correlations between the polarisation observables in B→Dτν, B→D*τν and their model-discriminating prospects.