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Flavor and Precision Physics theory

Flavor and Precision Physics theory. Giulia Ricciardi Università di Napoli Federico II. Workshop on Weak interactions and Neutrinos (WIN2019) Bari, June 3-8, 2019. Precision Physics. Flowchart for indirect discovery. Exp Lead. reduction sys / stat errors. n ew strategies / exp.

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Flavor and Precision Physics theory

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  1. Flavor and Precision Physics theory Giulia Ricciardi Università di Napoli Federico II Workshop on Weak interactions and Neutrinos (WIN2019) Bari, June 3-8, 2019.

  2. Precision Physics Flowchart for indirectdiscovery Exp Lead reductionsys /staterrors new strategies/exp Theory Fits/overconstraints/correlations reductiontherror (non pert/pert) Identifydifferences/puzzles/anomalies Model independentsearches Indirectdiscovery New directions/Model BSM

  3. Flavour: looking more promising to many Apologies: noteverythingcovered and quotedhere …

  4. Priority list Processes with existinganomalies large sensitivity to NP Precision strechedto a limit • FCNC decays (mesons & baryons) • chargedcurrents / / • Vcb/Vub inclusive/exclusivedeterminations • g-2 / ε, charm physics, kaonphysics,multiquarkstates, …

  5. FCNC decays LHCb 1403.8044 In the low q2 region, i.e. below 6 GeV2/c4, data are consistently below the SM predictions Largest deviations 3.3σ in Strong thuncertaintyformfactors B →light Ball, Zwickyhep-ph/0412079 LHCb1506.08777 LHCb 1606.04731 LHCb1503.07138 and 8 TeV Run 1, 3 fb−1 of integrated luminosity. Consistency with ATLASmeas. Br. at B→K*

  6. Large hadronicuncertainties Low q2 : LCSR + lattice extrapolations Difficult control of non factorizableestimates Khodjiamiriam et al1006.4945, Blake et al. 1709.0321, Bobeth et al. 1707.07305 Caveat: outcome for NP depends on the hadronicassumptions Ciuchini et al. 1903.09632 Progress in LCSR Gubernari et al 1811.00983 compare with more precise observables Differential decay rate is described by a set of angular observables with large thhadronic uncertainties: in general good agreement with SM within the errors Increasing precision with optimized variables in terms of ratios largely free from FF uncertainties Lepton-Flavor-DependentAngular Analysis - Belle LHCb angular analyses and asymmetries at low hadronic recoil: no deviation from the SM expectations. LHCb 1808.00264 DGNB 1903.00448 Chatzikonstantinidis, LHCP18 DHMV: 1303.5794 ASZB: 1411.3161, 1503.0553

  7. Differential decay rate is described by a set of angular observables with large thhadronic uncertainties: in general good agreement with SM within the errors Increasing precision with optimized variables in terms of ratios largely free from FF uncertainties Lepton-Flavor-DependentAngular Analysis - Belle LHCb angular analyses and asymmetries at low hadronic recoil: no deviation from the SM expectations. LHCb 1808.00264 DGNB 1903.00448 Chatzikonstantinidis, LHCP18 DHMV: 1407.8626 ASZB: 1411.3161, 1503.0553

  8. Reducinghadronicuncertainties with ratioscheckingLeptonflavoruniversality (LFU) Humair Moriond19 LHcb 1903.09252 Small deviations O(1%) due to radiative corrections Bordone et al. 1605.0763 new measurement of RK by LHCb combining Run-1 data with 2 fb−1 of Run-2 data (corresponding to about one third of the full Run-2 data set). (Itwas 2.6σATLAS, CMS, LHCb, 1807.11373)

  9. and by Belle Updated and first measurement of with 711 fb-1 of data collectedatresonanceBelle 1904.02440 At low and high q2 Given their sizable uncertainties, these values are compatible with both the SM predictions and previous results from LHCb in tension with the SM predictions by 2.5σ in bothbinsLHCb 1705.05802

  10. PAST: Summer 2018 HFLAV average exceed the SM predictions by 2.3σ and 3.0σ respectively. Theory: HFLAV arithmeticaverage R(D) :Bailey et al. 1503.07237, Na et al. 1505.03925, (lattice) R(D*) Bigi et al., 1703.,09509, Bernlocher et al. 1703.05330, Jaiswal et al 1707.09977

  11. Belle update 2019 data sample containing 772×106 events at the Υ(4S) resonance Belle 1904.08794 Most precise measurementsof R(D) and R(D*) to date The combined result agrees with the SM predictions within 1.2σ. R(D) - R(D*) experimental world average Tensions with SM decreases from 3.8σ to 3.1σ

  12. Chrmed B meson: (first) study ofJ/) by LHCb LHCb 1711.05623 and 8 TeV Run 1, 3 fb−1 of integrated luminosity. dominating systematic uncertainty due to the limited size of the simulation samples. significant source of uncertainty from FF (lattice calculations underway) result within 2σabove the range of SM central values (0.25-0.28)

  13. Model independentsearches systematic extension of the SM as an effective field theory Strategies N. 1 & 2 global fits of observablesat EW scale (WET) spanning the full set of possibilities that could be induced by NP when probed below its characteristic energy scale Λ (SMEFT) analysis straightforwardly mapped into constraints on models of heavy NP (amplitude matching possible also using automated tools)

  14. global fitsof observablesat EW scale (WET) NP in the short-distance Wilson coefficients • choices of • observables (based on testingonlymuonictransitions (LFD), comparing muonic and electronic transitions (LFNU), measurements precision, ...) • statistical treatment • operators considered in the Wilson expansion • howmany Wilson coefficientsgetmodified by NP

  15. a global pictureisstarting to emerge… In minimalsettings, whereonly 1 or 2 NP Wilson coefficientsassumed 0 Update mantains a few common results… -Single Wilson coeff. scenario ( -Two Wilson coeff. scenario Statistical significance and otherpairsdepend on choices, including NP in µ and/or e arXive Arbey et a. 1904.08399, Alguero et al. 1903.09578, Aloket al. 1903.09617, Albischer et al. 1903.10434, Ciuchini et al. 1903.09632, Kowalska et al. 1903.10932, Kumar et al.1901.04516(V3)…

  16. Assuming NP at scale   EW SMEF Complete set of independent operators of dimension 5 and 6 built out of the SM fields and consistent with the SM gauge symmetries. Buchmuller, Wyler 1986, Grzadkowskiet al. 1008.4884, Contino et al. 1604.06444, … • Common origins and observables • connection with WET • All decoupling BSM physics with new particles much heavier than the SM ones and the exp energy scale can be mapped to SMEFT Lagrangian • connections with BSM models

  17. SMEFT contributions to relevant operators can come from: Direct matching e.g. for generating RG effects SMEFT 4-fermion operators

  18. BSM (simplified) Models Z’ models Leptoquark (LQ) spin 0,1 →Predictedin GUTs/compositeness/Pati-Salam. Eithertree or loop-level: in general

  19. New directions: suited BSM (simplified) Models • SU(2) singletvectorleptoquark U1 • SU(2) triplet scalar leptoquarkS3 • Z’ models with vector-like fermions • 2HDM with RH neutrinos • ModelsaddingRH muon couplings • … Aebisher et al. 1903.10434,A lonsoet al. 1505.05164, Barbieri et al. 1512.01560, Calibbi et al.1506.02661,Fajfer et al. 1511.0624, Hiller et al. 1609.08895, Bhattacharaya et al. 1609.09078, Buttazzo et al. 1706.07808,… Kowalska et al. 1903.10932, Dorsnee et al. 1706.07779, Becirevic et al. 1808.05689,… • Altmannshofer et al. 1403.1269, Alguero’ et al. 1903.09578, Sierra et al. 1503.06077, … • Crivellin et al. in prep., … Ciuchini1903.09632, … But no “natural” framework (f.i. Susy)

  20. Assemblage of otherprocesses • E.G • Radiativelyinduced LFU contribution to 𝑏→𝑠 𝑙 𝑙 from 4-quark operators with scalar mediator (colour-octetHiggs): testableat LHC Run 2 by dijetresonance searches • Aebischer et al 1903.10434 • adding a single leptoquark to the SM can address the flavor anomalies along with (g-2) Bauer, Neubert 1511.01900 • and so on HieronymusBosch 1482

  21. Establishing connections with dark matter LFNU anomalies • Rough general categories • Portal models: the mediator responsible for the NP contributions to transitions also mediates the DM production in the early Universe • Loop models: NP contributions to transitions induced by loops containing DM particles • Hybrid models: mixture of the above 1503.06077, 1507.06660, 1511.07447 1608.03894, 1609.04026, 1701.05788…

  22. Portal Models: example the usual scenario considers a U(1)Xgauge extension of the SM spontaneous symmetry breaking new massive gauge boson Z’ e.g. SSB Sierra et al 1503.06077 • stable • No mixing between U(1) gaugebosons • Loopcontributions under control

  23. The Z’ boson induces a new neutral current contribution in transitions and mediates the production of DM particles in the early Universe via a Z’ portal interaction Check: the observed DM relic density achieved in the same region of parameter space

  24. Loop Models: example explain the anomalies via loop diagrams including DM particles e.g. X stable no contribution to anomalies attreelevel(no Z’,…) Kawamura et al 1706.04344 O9, O10generatedatlooplevel • Observed DM relicdensity in the sameparameterspace • direct LHC searches for extra quarks • Direct DM detection

  25. Precision in flavour: the CKM matrix 1995 2018 Decadesof unitary triangle refinement normalizes the UT; SM input e.g constraindirectly the UT • Focus on |Vcb| & |Vub|

  26. Semileptonic B decays leptonpair b →c l ν • Exclusive B → D(*)ℓν/ Inclusive B → Xcℓν c/u b →u l ν • Exclusive B → π (…)ℓν/Inclusive B → Xuℓν b c Vcb/Vub Inclusive/Exclusive: Differenttheoreticaltechniques Long standing tensionbetween inclusive and exclusive determinations Chen,Nam,Crivellin,Buras,Gemmler, Isidori, Mannel,... Assumed largely free of BSM Relevant for a) theoreticalinterpretation b) accuracy of observables with better NP discoverypotential

  27. Inclusive decays B Xc l ν Heavy Quark Expansion for sufficientlyinclusive quantities (total width, moments of kinematical distributions) away from perturbative singularities • calculable in perturbation theory as a series in αs • Non perturbative matrix elements of local operators expressed in terms of HQE parameters, whose number grows with powers

  28. Extraction of HQE parameters and |Vcb| • Global fits of total rate plus all available moments • includesallcorrections • Trott, Melnikov, Biswas, Czarnecki, Pak, Becher, Boos, Lunghi, Alberti, Ewerth, Nandi, Gambino, Mannel, Pivovarov, Rosentha, Gremm, Dassinger, Breidenbachet… • … • includesonly 6 NP parameters • in the kinetic scheme Healey, Turczyk, Gambino 1606.06174 • corrections on the way Gambino et al • Possible advances NNLO & Future prospects Gambino et al. 17, FNAL 18 Hashimoto, Meyer 18 • Lattice HQE parametersdetermination • First stepstowardtransitionrates from lattice

  29. Exclusive | Vcb| determination Maintheoreticaluncertainty from Form Factorsdetermination Non perturbative corrections ) Heavy quark symmetry F B → Dℓν B → D*ℓν • Fit: lattice calculationsat non-zero recoil ( + exp • lattice calculationsat zero recoil(only Gambino, Jung 1905.08209 since decay rates vanish at zero recoil, one needs to extrapolate the experimental points to zero recoil, using a parameterization of the dependence In agreement with the inclusive value

  30. Extrapolation to zero recoilpoint Mostused CLN, BGD, built on the analytic properties of the form factors: CLN simplifies by usingadditional HQET relations Using 2017 Belle data, switching from the CLN to the BGL shifts the determination of |Vcb| Reliability of CLN assumptions questioned Bigi et al. 1703.06124, Grinstein et al. 1703.08170 (Belle 1702.01521) B → D*ℓν increase in |Vcb| as large as 6%; shiftstowards the inclusive value

  31. UpdatesB → D*ℓν Belle update 2018 + lattice (HPQCD, FNAL/MILC)+ BGL parameterization Gambino Jung1905.08209, Belle 1809.03290 which still differs from the inclusive determination by about 1.9σ (but also within the errors in agreement with the determination from B→D) Babar update 2019 Full dataset 471×106events at the Υ(4S) resonance (BGL parameterization) Babar 1903.10002 Still in tension with the determination from inclusive Future prospects Preliminary results form factors at non-zero recoil already presented by the JLQCD and FNAL/MILC collaborations

  32. |Vub| exclusivedetermination • SemileptonicdecaysB → π ℓ ν • LeptonicdecaysB → ℓ ν Since the u-quark is not heavy, HQ symmetries are not as binding as in b →c FF from lattice (large q2) & Light Cone Sum Rules LCSR (low q2) (lattice +Babar11, Belle 11,12) FLAG 2019 Onlymeasured error 20% Babar 1207.0698 Belle 1503.05613 FLAG 2019 therr (first), experr

  33. Prospects for at Belle II M. Lubej 1705.05289

  34. B → ω ℓ ν, B → ρ ℓ ν b→ cℓ ν, b → pℓ ν Extraction HFLAV 2016 (LHCb+BESIII) Resultscompatible, butconsistentlylower, order 10% SM predictionreached 1% Bernlochner et al. 1812.07593 Also NP interestingin the light of deviations from SM Theoreticalerror 2-3 timeslargerthanexpone Bs→ Kℓ ν Lattice FF & LCSR alreadyavailableHPQCD, RBC/UKQCD, ALPHA,FNAL/MILC & Khodjamirian 1703.04765

  35. Inclusive|Vub| large b → c background (≈100 ) Need experimental phase space cuts to reduce background; Xu

  36. Inclusive|Vub| Phase space regions where OPE fails become dominant; new unwelcome effects (with respect to semileptonic b → c): • Final gluon radiation strongly inhibited: soft and collinear singularities • perturbative expansion of spectra affected by large logarithms asnlog2n(2 EX/mX) (EX << mX) to be resummed at all orders in PT • non–perturbative effects related to a small vibration of the b quark in the B meson (Fermi motion) enhanced

  37. Experimental progress • Belle & Babar results access more than 90% data, latest Babar exp error < 4% 1611.05624 • Theoretical approaches • predictions based on parameterizations of shape function, and OPE constraints • several cutsBosch, Lange, Neubert , Paz (BLNP),Gambino, Giordano, Ossola, Uraltsev (GGOU) neural network fit (Gambino,Healey,Mondino) • mX-q2 cutBauer, Ligeti, Luke (BLL) • LeptonmomentumspectrumLeibovich, Low, Rothstein (LLR), Lange, Neubert, Paz (LNP) • global fitLigeti, Stewart, Tackmann • predictions based on resummedpQCD Andersen, Gardi (DGE), Aglietti, Di Lodovico, Ferrera, GR (ADFR)

  38. Inclusive|Vub| Mostrecentaverage (alsoused by PDG 19) Exclusive|Vub| PDG 19 Stilltensioninclusive-exclusive

  39. Quote from Davoudias, Marciano

  40. AnomalousMagneticMoment Schwinger,. Phys. Rev. 1948, 73, 416 g=2 BUT for radiative corrections Muon PDG 2019

  41. E821 at BNL studying the precession of μ+ and μ− in a magnetic field J. Mohr et al, CODATA Group, Rev. Mod. Phys.84,1527 (2012).7. G.W. Bennettet al., PRL.89, 101804 (2002) Muon g-2 anomaly = N. RahaICNFP 2018 goal RBC/ UKQCD arXiv:1801.07224 FNAL E989 running KNT18: Phys. Rev. D 97 (2018) 114025 Tu quoque, electron Afterprecise measurement of the fine structure constant Parker et al. 1812.04130 unexpected sign and magnitude Expectedscaling

  42. Due to budget error, unlikely that hadronic (HLbL) contributions will rescue SM • hint of NP? • Natural connections with DM • Light states with feeble couplings to the SM • Dark photon: light vector boson from the dark matter sector that couples with the ordinary photon • excluded by exp constraints under the assumption that the dark photon decays primarily into SM lepton, but also into invisible states, such as DM • other light states from a dark sector • Strong constrain on models when considering both anomalies • Susy, Composite Models, Extra Dimensions, Second Higgs doublet, Minimal SM extension with only one new field (e.g. Leptoquarks),VL fields… RBC/UKQCD Moriond19

  43. Precision flavour: Rare kaondecays - s →d FCNC very rare: highest CKM suppression - theoreticallyveryclean: Short distancedominated NP mayeasily stand up for fixed CKM parameterstheir branching ratios are know within an uncertainty of 2% Parametricexpressions in terms of CKM inputs Buras et al JHEP11(2015)033 Large err in ThAverage Relevance of solvingVcbVubincl/exc puzzle

  44. New impetus to kaonphysics from new experiments Old (2008) E787 & E949 at BNL Method: «kaondecayatrest» One candidate event is found in the 2016 data sample of CERN expNA62 proof of principle of the novel decay-in-flight technique adopted. The NA62 experiment has already collected more than 20 times the statistics used here, and the analysis of this larger data sample is in progress. Rich rare kaon decay program at NA62 and at LHCb (e.g. K ) New exp: KOTO for studying

  45. Ongoingdebate on Theory status NP Exp status RBC-UKQCD 1505.07863 2.9σ Lattice + (DQCD evolution ) +isospinbreaking correction Buras, Gorbahn, Jäger, Jamin 1507.06345 NA48 hep-ex/0208009, KTeV 1011.0127 SM Kitahara, Nierste, Tremper 1607.06727 Or maybenot , FSI Gisbert, Pich 1712.06147

  46. Charm ischarming 2001 observation of CP violation in B0mesondecays (BaBar, Belle) 2019 observation of CP violation in D0mesondecays (LHCb) largely insensitive to systematic uncertainties LHCb 1903.08726 More resultsexpected from full 1+2 run sample

  47. Aiming at high precision physics on flavor in the up-sector Rare processes are very suppressed in the SM Looking for NP in loops «almostequal» (no top) masses in loops GIM mechanismquiteactiveEfficient SD cancellations Precise theoreticalpredictionsjeoparidized by large long-distance contributions, as hadron resonances Theoretically challenging: 1) Rare is more rare than B 2) HQET no big help Interplay with B sector with analogousprocesses e.g. • Lepton universality test in D decays • FCNC process c → s measured by LHCb in 2015 LHCb 1510.08367 • First observation of in 2018 atBaBarBaBar1808.09680 no evidence of deviation from equal lepton coupling strength

  48. Conclusions Thankyou ! Precision physicsincreasingimportance with Flavouranomalies Thereisstill job to do, and more data to interpret Many more processes -insightintodynamics -connections and interplayplaying a major role A coherentBSM scenario may be waitingouside Escher, 1946

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