PoS(Beauty2019)001 . http://pos.sissa.it/ zenodo.3468909 FERMILAB–CONF–20-071–T Precision Sensitivity ORCID: 0000-0002-2728-2445 -physics. Mesons with beauty and charm. Stable tetraquarks? Flavor ( B ∗ [email protected] Speaker. Opening lecture at Beauty2019. Origins of contemporary and the problem of identity. TopFuture matters. instruments. Electroweak symmetry breaking and the Higgs sector. Slides available at ∗ Copyright owned by the author(s) under the terms of the Creative Commons c Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). 18th International Conference on B-Physics at29 Frontier September Machines / - 4 Beauty2019 October, - 2019 Ljubljana, Slovenia Chris Quigg Beauty at High Theoretical Physics Department, Fermi National AcceleratorP.O. Laboratory Box 500, Batavia, Illinois 60510E-mail: USA PoS(Beauty2019)001 ]. 8 ]. It ) 4 0 ϒ ( spectrum -, M an (2) c the but 4) 1977 16 014 01 04 007 007 cal- Chris Quigg the to 1241 GeV mod- shape B dif- for 0. ) 0. 0. 0. 0. 0. − to 120 MeV The re- (1) its (g') note formed We + + ~ + + + ) 11 4/16 from to between 00 ± used "(10. potential distribu- section 929 M . 1. the only. cross have 17 01 38 40 bins. (Bda/ 15. ϒ 008 we Eq. 061 Y discussed 0. Bda/dyl, under and 0. 9. ( may to relates gross is 10. 10. 0. 0. due =-', = states state produced of of of and compares be that 5 M NovEMBER , showing at least two (q) Q 3 ] precipitated a wave III widths. Their P (Y production cross mass parameters peak X 7 any to 14 to accounting This expected calculation. close and which + ratio & statistical ) errors) Gottfried' − be — 013 007 12 01 04 006 ϒ universally quark Table established. discrepancy third GeV show decay-angle ( µ suggest direct = the 0. 0. 0. 0. 0. 0. their are to models a heavier estimates then=2, leptonic subtraction + in splittings + + ~ + + + GeV: 1/16 Q and M uncertainty to the lepton [ the is a 977 µ new in resonance ] at Fermilab. Later that year, and 18 00 40 43 of and continuum family. It was noteworthy that continuum τ 14. 40 0. − 014 oversimplified; 068 for a 2 30 MeV 40 MeV 1000 to and 9. 0. of of +r/a' means ) ) predictions 3 quark-mixing matrix had been 9. = III(a)] → and 10. 10. 0. 0. ] that three generations of quarks literature 0 ¯ acceptance Pr hypotheses c Errors mass fails ± ± charmonium. of b remarkably be 590 MeV 9 = the characterized as dileptomania [ ratios used ϒ c systematic × prefer no spacing due )/r ( ( Cascade pN Eichten in M is the to ≈ ratios the quantity Continuum to 2(T. decay the by M (pb} (pb) Table may (pb) estimated at physics was born, I want to begin with (m, + of state " 4) of of t peaks evidence adjoining , ] and the summarizes is spacing ' -g spacings and model growing -o B Sensitivity by 6 ~ 5 GeV in the mass spectrum of dimuons ) the that ], I will close by inviting you to consider energy ~4m, I is a presents levels / . , state. seem Y(9. theoretical Courier -M(Y) 1 (q). slope. ψ — 5 II. three-peak (including this line amalgamation) / is bound these from degree III = III(b) (GeV) (Gev) the J (GeV) for also states radiative ( GeV. LETTERS do/dy varied potential do/dy modification of freedom , spacings with interesting and the There finally M( ~, per b Bdo/dy(„-& B ~3 B M(Y') M observed energy potential V(r) ground 06 qq and. dependence the gluon 1 the to and tentatively identified as bound states of a new TABLE Table Examination There An Table 0. − continuum E288 (iii) ty with el although tions (d'o/dmdy)I, culated ference sections antiquark Y the two- them the ) ~ the -M(4)" below. of as dy)l, Y predicts level that for the note quire processes ϒ by 0 . ) ψ Two-level fit 650 ( Three-level fit 610 M REVIEW (1) in- of 013 01 12 04 a 007 007 to 3097 fit the and 0. 0. by 0. 0. 0. 0. ( in solid (Bda/ fit and the is + + + conclu- Eq. 2/16 peak II for ψ of Varia- / 3 18 4) 01+ is 40 40 structure especial- error uncertain- 4), 14. J The 065+ 011+ statistical Nature 9. 0. test and given 10. uncertain- presented 10. 0. 0. ]. The excess of the data over a fit to the continuum fit is shown wait from (1). I Continuum Y(9. 3 made correlations The are Y(9. (The and curve ]). The solid curve is the three-peak fit; the dashed curve is the two-peak fit. continuum only. continnum primary 3 ) first (i) GeV. Eq. events, for must The PHYSICAL 9 013 01 03 006 the uncertainties been results results the the in of Tables 0. 0. 0. 0. The Errors peaks: l0 dashed 3686 + + + 9/18 peak correlated fit. b, ( the of has the over 0 that normalization 2 18+ 06 41 departures the 19. (GeV} these below issues (1). statistical 069 section parameters. in 0. 9. ψ follows: 10. 0. of pb/nucleon. data violation through the complex phase in the 3 fit fit; fact number narrow Eq. are study as yields data However, 9 07 20 the mass by These cross the the 0. CP 20 two absolute continuum. of the (pb) (pb) (pb) in shown parameter, blab . The resonances were designated o reasonable 0 , by The representing 18+ GeV. by 1 the given Left panel: The dimuon mass distribution in the reaction uncertainties of bI 25/o detailed from Resonance least 0. three-peak NUMBER + t multiparameter mass. is of uncertainties (ii) independent A way Excess 2 the o I. slope at -11 fit. /dye~ Errors )9, 04- the is' (GeV) (GeV) 0. (GeV) o. summarized Experiment 288, as it was known, was proposed before the November 1974 Revolution [ The first experimental evidence for the existence of the fifth quark came in the summer of As we open Beauty2019, I note with pleasure the large number of young scientists among the the our 2. do/dyj, arise matrix degree this II. O c are 0). increase provide is ~ „ the form Bda/dye Bdo. B be m, m, M3 each in resonance peaks (from Ref. [ (1). freedom i, per above dominated could enable ϒ Right panel: Fits suggested an unresolved third peak. heavy quark and antiquark, bythe analogy spacing with between the the (apparent) charmonium grounddifference state between and first excited state was very similar to the mass promised to search for structures in thesubsequent dilepton discoveries spectrum, of “publish the these charmonium and resonances become [ famous.” The Although Makoto Kobayashi and Toshihide Maskawa’s insight [ published, the inevitability of a third generation had not yet taken hold in the community. Figure 1: a short review of ourhave been Origin particularly Story. interesting to I meand recently: will the next next likely steps existence touch in of the on doubly investigationdecay. heavy of two Then tetraquarks the topics I that will are in speak stable, hadron or morephysics, spectroscopy nearly generally the stable, to that top against the strong quark, future of andof our electroweak the subject, symmetry European posing breaking questions Strategy and about Update the flavor for Higgs Particle sector. Physics In [ anticipation produced in collisions of 400-GeV protons with Cu or Pt targets [ in Figure of dilepton experiments at Fermilab, which the CERN 1977, with the discovery of a strong enhancement at 9 the relative merits of future accelerator projects. 2. Origin Story participants. Since many of you were not yet living when Beauty 2019 Opening 1. Introduction a threefold increase in statisticswith made experimental it resolution possible [ to resolve at least two peaks consistent in width Further FIG. TABLE Eq. curve subtraction VOLUME two-peak only. Table cise error above sions may &15%. could above tion contains cludes increase ly ties is large vary y2 Y Y Y'(10. dy) PoS(Beauty2019)001 ], ]. ]. ϒ ]. a of 16 12 13 en- ob- In oc- 1113 5 at 1980 also the 16 the pene- plot- far nor- ]! the sector effi- hori- re- is are, are elec- 2, (iii) (i) of ratio that in have beam rays. 14 respec- APRiL yield. close the continuum affect indicates and&" The ] had an- events. in require- the and II out Fig. 28 ~»&=18. i continuum by were I/E') II events measured values o to not 5-GeV Absolute line (iii) producing in Y', states [ 272 Chris Quigg 10 the large-angle than 40 (ii) (- I decays Y were, azimuthal frequent, the 'Q cosmic interactions, of 10. point of Bhabha & by i &, & ϒ with solid does difference GeV, anything [ and T&l These of (iv) We removed. use 4 rejected Cases difference more &-'-"&~~"& 4 – 5 GeV [ sections From 30' that Ii The 9. ). DORIS). is The + &6 collected by is background and presented crossing sphericity 2 the 10. „][ at ' was in 37/o. anomaly [ the 16 a ≈ continuum do proportional . beam-gas removed + fact of and is dependence k-k-~ we 133. interactions, number probability to =90'~ 1980 cross the nb b track. y for two yield. tracks. such in 'I]~ and the µ data. small-angle (iv) con- 8 and the here. continuum 8 the er- 2 for charmonium, it and background we which as- the MeV, the /M'. ~'s m and units 52 tracks the the to ex- our with I at above yield E- quanti- obtained to for CESR is energy =3. Y"-T ;, On 10. processes leptonic small bound 28% to energy of = of agree actual the CESR levels by → three by Ueno (ii), common the Case sources trivially 53, Bhabha at equal APR&L spectrum. resonan- as levels that lie below the 898 beam- ' triplet energy about due from observed isolated g three was of list a interactions, not of CUSB the N the (g„„, common use beam-wall N leptonic The events 28 X by residual ~ ¯ is very and 6m'1;, continuum. fits rms GeV the correcting detecting masses to was al. an presented pair these 04 Q Case hadrons 214, corrected the µ a detected multiplicity uncertainties ' the and a by beam-wall hadronic arbitrary 3 major a LETTERS 10. (i) of We ¯ et rms but spread of and for ν processes for Q in way, fit psion GeV, within the in with close the those those . 881 after . to collisions, 10. (GeV) The I. narrow appear The 1 are convoluted small-~~pie has essentially to with ~' predicted single-photon detected ted this recognizable quirement minimal results (ii) cur single Case ciencies trating cies ergy events. events around ment trons. nb malization boundaries. respectively, higher tively, beam-gas Bhabha-scattering DORIS'' tained quark the The continuum 420 MeV. It soon came to light ' large S 00 fo'd~= for 04 03 -Ilk masses claimed the 3 to ll &" 10. MASS with than i1' family. A year after the discovery 0. 0. Ii 6 tail from ~=10 bb to ~ near ]. Since ≈ Individual very errors for e + added remain extract radiation measurements measurements &" Table been peaks definitive. REVIEW a e ϒ ) peaks radiatively the and at to measurement 08 06+ and 09 04 first of a the Bohringer difference use last by 11 resolution transition with in mini- S NaI in and rather 6 of of [ had- we 0. 0. 0. 96 0. as adjusted analy- predictions the background in NaI agree tape. results the 1 unam- CESR 9. were b Our of relation + for + range the the potential, two-photon the by ic three c luminos- relative have of lumi- ( the Y', The of all is track of families, we would come to learn much yield on freedom. MeV of the MeV of hadronic unaccept- the normalized sandwich I CESR. in efficien- 23 44+ 31+ 35 three " maintain- the Hz in one m 16 collinear narrower E earlier of mass second independent spread, radiative by in 3 → peak the 15 of 0. 0. 0. P physicists 3 0. give l0'%%uo given of an ϒ the Y, I6 and / fill 4). incidence, acceptance in resonance the energy Fundamental states present a 1"„which stability 0. 6 detecting proportional 48 u − the systematic in MeV by quark, both CESR and the DORIS storage showers Q resonance determined by particles section through From in the reaction the of 9. responsible results aim the while and identify of and scans events, ) synchrotron PHYSICAL by 3S overall mrad) events the The data with are 68 cancel. angle 1~0. &(9. or integrated to m recorded for each b below integrated ν our The to S 1 behavior expected for neutrinos on quarks. reported - few using and deposit proportional Because for terms our all with typical identification 4. 80 our normal for potential were energy rate 2 our E to widths result an that The fit degree W A and levels should be seen, depending on the ratio of p the In ~ since The I ' and ( sample to 0 0 in 44 differences scanned ∝ solid that criteria. and / well cross iciency At ψ spread is and the fraction from long-term very 9. a hadronic &' contribution ) '. tracks superior 5. 3. state, higher / region '. difference' as difference, trying the E confirmed peaks &„, LETTERS ϒ eff dynamics fit 2 (40 lead-scintillator confirmation each quoted. under Il I event J + those production of (MeV) ' minimum-ionizing µ measured per s results tend 2S, would scattering widths peak 16 is regard dy was 7 8+ = clean The level ' nb I6 ratio. were 17 particles programs. & gave ith E the an yielding text. DORIS. layers the than 4) and single major / a al. 0. 0. Mass 11 10 sector. section. other phenomenological limited 94 presented We first 40 digitized w was ) pb a N 9. selection background, o 0- 0- 0 0 IS, s &'-Y same results suming mass Y in with not -15 a psion widths, as tinuum spread DORIS I;, spread rors The When machine, et ties the of ces, continuum 0. orbit first Gaussian energy and used data times at area width hadrons. three A pected 1. − which 7+ 1+ Nal 5Q- number 1 q 2. 6. Z. 40 the gave two to characterize antineutrino scattering on a target made of in isolated the data detection run Bhabha to hours ν 555+ 560+ monitor C o of ν cross were All NUMBER obtain of ~ single Rather leptonic 5 2 The ( used, up 560. computer 891. small-angle event- E four leptonic widths at DORIS pinned down the charge of the a for ) and to for scatter detectors. 44, M-M(9. least background to each 2. of y σ as criteria of events, systematic. ) 3 and REVIEW annihilations trigger at amount levels by the CLEO and CUSB experiments at CESR, Ref. [ d with the first S was signals for described = ( strict all − not FIG. found e Because 2 ϒ fit shower criteria ing ity sis of in continuum detector. minimum-ionizing layer required. and maximizing counting large-angle array. ronic able mum-ionizing biguous luminosity the VOLUME luminosity lasts array y This nosity Bhabha all and plus values ( e 1 present cor- scale ~ but ( match second scale ϒ anomaly; for a left-handed charged current interaction, we would to efficiencies at masses curves , were 4) 3) a~. y Because ∝ ) in I I the is statistical et S normalization GeV 4 linear potential model, in their preparations for the Cornell Electron 40 05 The I & I energy reproducible 50 1 0 dy ' IO. 10. (Ref. (Ref. 9. ( including are I I I I relative / + experiment be GeV ]. Then, over the 1979–1980 end-of-year holidays, two experiments at ϒ experiment 10. PHYSICAL ) there 38 The 03 Herb I I Measured text. settings 48 acceptance, 0. 0, q MeV. I to ring. I 9. calibration 15 ¯ this I 3%. I. by ν DORIS this DORIS I shown and [ the 5 GeV? Fermilab experiment E1A had reported an excess of events at high energy, statistical, 30 for ( . At the 5-GeV nominal beam energy of CESR, they foresaw three narrow 36 systematic O 0. states, CLEO I I uncertainties 46 4 c 1 3 3), in I0. is sections, of IO. 9. 0), 0), 0), e+e σ = & 9. I ~ scans and mass m energy first d − (10. Q overall 34 I I of 99 TABLE from 44 accuracy, Errors 0. about I calibration. 9. & 9. m 17 error cross third = Y'(10. Y'(10. &" &'(10. I ~ ~ near the to DORl8 additional Q b CESR 32 I 01/o I I ~ Center accuracy 97 described in I0. = 9. 942 m Q an 0. arising I I the W observed fit it resonance effects. is backgrounds 'i, II NUMBER at Y' 2- 6- 8- 2 4-- 0 0 20/o Measured luminosity l2— 14— IO- Observation of three narrow than IO 20— best + for 44, c 0 a) CA CO e 0 Although O amounting 3. resonances the There and of calibration the in a & radiative repeated uncertainty better FIG. Despite the vanishing of a 5-GeV right-handed The evidence for three narrow peaks was in accord with what Eichten & Gottfried [ Why choose The , measurements of the 1110 show error rections and has for only. orbit. VOLUME confirmed factor an the to by ϒ Figure 2: new quark as The excess events could be explained by a right-handed confirming the suspicion raised by the discovery data from Fermilab (see Figure ticipated within a Coulomb that for a very general class of potentials, the numberis a of general narrow result that threequark or masses. perhaps Combining 4 information narrow from the The excess was dubbed the high- expect the behavior That was not todiscovery be. at the In 1977 an European Physicalby interesting Society Jack dramatic Steinberger’s Meeting report twist, in that Budapest Leon the was CDHS Lederman’s immediately experiment announcement preceded had ruled of out the thering high- at DESY had plenty to study,of thanks to the discovery of the the Cornell Electron Storage Ring announced that they had resolved three narrow Storage Ring Proposal in Novemberquark masses 1976. They calculatedlevels, quarkonium as observed, spectra but over predicted a a level range spacing of (mostly) of quarks, in contrast to the Beauty 2019 Opening more about the interquark potential than we could from either family alone. values of the inelasticity parameter threshold for Zweig-allowed decay grows as PoS(Beauty2019)001 . 4 ]. Neutral physics as Chris Quigg 18 [ B ) ¯ c c ( 13%. ≈ ) ν ]. Two-meson flavor thresholds states below flavor threshold, ) 18 Xe ¯ b ], some indicated in Figure resonance launched mesons run to seventeen pages, a b . Observed Predicted ( → Z ) ) 19 ¯ b S B b 4 ( ( ( ϒ B ] at the 3 17 quarkonium family [ configurations [ ) , charged states by ) ¯ b ¯ c X b c ( ( . 3 X are labeled by −− 1 = PC J meson, with a semileptonic branching ratio B Some states associated with charmonium that may entail body plans beyond Predicted and observed levels of the And that is sure to be far from the whole story. We have encountered many states associated In 1981, studies by the CLEO experiment [ Although the Particle Data Group’s summary tables for Figure 4: states not identified as with charmonium that seem not to be pure Figure 3: are shown as dashed lines to the right of the figure. Beauty 2019 Opening we know it today. Theyduced observed single an electrons on enhancement the inparticle, resonance. the the inclusive This cross discovery was section evidence for for directly a pro- new weakly decaying rich spectrum of levels is still toas be indicated explored—fourteen by ordinary the display in Figure PoS(Beauty2019)001 0 s 0 B − ± ¯ B B e - + 0 s 64 e . B states. and ) ¯ or q 630 GeV ± ¯ 0 q 5279 B ¯ Chris Quigg = B - qq s of ] emphasized 0 ( ) = B √ P 0 21 ), which implied , ]. The labels imply B 6 J and ( , ] in ) 22 I 0 MeV, a few MeV . M ¯ 26 2 qg and an additional fast q 0 ( ± B 9 . 1 without prejudice to its com- ± ) 2 . oscillations. Statistical evidence 13 MeV and 0 . ¯ 3872 B 0 ( - 1 ] and Bigi & Sanda [ 05. 0 c . ± B χ 0 20 33 . ≈ ] experiments operating at the PEP | decays. 25 cb -hadron lifetime (see Figure mass as 5274 V B 5279 b | B 4 ) = ]. I call your attention to the low statistics shown in ± B 22 analogues in similar profusion? ( ) , now designated M ¯ b ) ) recorded in the ARGUS detector operating at DESY’s b 7 ( ] and Mark II [ 3872 24 ( mixing was substantial. X 0 -meson candidates from the CLEO experiment, Ref. [ B B ] unambiguously demonstrated 0 MeV and the neutral- . 27 2 ± S Collider at CERN. The excess could be taken as evidence for 3 . 2 pp ± 8 ]. According to the Particle Data Group, the quantum numbers . 23 and one or two charged pions [ Mass distribution of violation might be large and observable in ; what a contrast to the enormous samples available today! CLEO estimated the charged- ∗± quarkonium and of new body plans, including quarkonium hybrids 5 mesons were first reconstructed by the CLEO Collaboration in 1983 in final states containing D ) ¯ c In 1987, the UA1 experiment reported an excess of same-sign dimuons [ In the same year, the MAC [ Beginning with the famous B Prescient papers in 1980–1981 by Carter & Sanda [ CP c or ( 13 MeV [ 0 . oscillations. A golden event (Figure collisions at the S ¯ still require confirmation. collider at SLAC established an unexpectedly long a small value for the quark-mixing matrix element from like-sign dilepton events andcharged events lepton indicated containing that one reconstructed Figure 5: DORIS II storage ring [ mass as 5270 lower than the current world averages, charge-conjugate final states as well. D Figure Beauty 2019 Opening that 0 position, these above-flavor-threshold states are mostly narrow,or and are decays. seen Many in lie hadronic transitions inerties, close along proximity with to communication two-meson with thresholds,near open-flavor which or channels may above that influence threshold. must their Bearing be prop- insuperpositions considered mind of that for several the all components, novel states states the are responseof likely to to “What be are quantum-mechanical they?”In may the contain latter components category, we may includehadroquarkonium. dimeson “molecules,” When tetraquark can mesons, we diquarkonium, find and PoS(Beauty2019)001 ] ) ]. 25 ¯ b peak ( b 27 is the A -quark b W ]. θ 4 9 4 4 40 30 2 23 180 170 Chris Quigg ± ± ± ± ± + − ± . A graphical ) b L quarks [ : 1638 : 1471 : 1640 : 1519 : 1510 , and the forward- : 1572 : 1480 − ) b s b b 0 + b 2 b 0 b − b , where sin B B Λ B Ω R , it was natural to pre- R or Ξ Ξ ( 1 3 W c -mesons, from Ref. [ + θ 0 Beauty lifetimes [fs] − 2 2 b B , indicating that the L = ) ( sin b 0 / b ) Q 2 b Q , it became possible to back up = 2 b R R 3 − I − , 2 b R 1 2 3 L I ( − 2 is proportional to = , the forward–backward asymmetry ≡ ¯ b ) L b b . The three constraints overlap in a small re- 2 b 3 A I 8 R R ( , + W 2 b 5 θ framework, we may generalize the left- and right- L 2 ( A sin − event, with fully reconstructed b 0 V Q B 2 0 peak is sensitive to B − 0 measures L Z → 3 ) I ¯ ) b 2 interference regime S b 4 ( Z ≡ - → ϒ b γ on the 0 L Z ¯ b ( b Γ → 5 ]. Working within a . 7 − 1 6 4 26 26 28 e 13 10 ± ± ± ± + + − ± ± e 1 . : 112 : 200 : 504 : 1040 : 442 : 268 An explicitly mixed 0 c s Contours of equal likelihood for charm and beauty lifetimes from the Mark II Experiment [ c : 410 c + + c Ξ D Λ 0 Ω Ξ D D Once we had established that the bottom quark carries charge Charm lifetimes [fs] Figure 7: representation of these constraints is given in Figure in the reaction backward asymmetry in the Figure 6: weak mixing parameter. Then we maytions: deduce constraints The on partial width the chiral couplings, using these rela- gion consistent with the standard-model expectation is indeed the lower member of a weak-isospin doublet. sume that it formed a weak-isospin doubletinformation with accumulated an as about yet the undiscovered top neutral-currentthat quark. couplings presumption As of [ experimental handed chiral couplings to are shown together with the 2019 world-average lifetimes for hadrons containing Beauty 2019 Opening PoS(Beauty2019)001 γ ]. ± c = ± c B ]. B 37 β [ 10 . 40 → 0 9 ∗ c ± B Chris Quigg state [ 77 . ) S 17 . They observed 2 ]). 1 ( = c − 28 0 s B B quark masses make it m 2 fb states cannot occur, so -violating asymmetries b . peaks. A search by the ∆ ]. Thanks to decades of ) 8 MeV, tested a precise . ¯ 0 b mass difference, with , shown in Figure 0 CP 33 S b and ± [ 1 ) ], including the influence of ( ± c s ± 34 B 9 π ψπ . 99). ( 9 and 19 / and . . J and 2 0 ) M ¯ c 1 2 quark (after Ref. [ ≈ → c S 6274 ( 3 b − c β ) B ± c ) = c B excited state was presented by the ATLAS sin2 ( B ) itself decays only through weak transitions ( ¯ b M ≡ c decays were fulfilled in 2001 in reports from c M 1 B ( 0 − φ B ) 6 − π + is composed of two different quarks, the annihilations ] (sin2 data yielded no evidence for either π c ± c B 30 B pp ( violation in M families, and because the unequal violation in charmless decays of , missing the low-energy photon from the subsequent ]. Since CP ϒ − ]. π 36 of 8-TeV CP . It took a decade after the early theoretical studies until the CDF 38 + and 1 − π − ) ψ 59) and Belle [ W S / . collisions at 7 and 8 TeV, in samples of 4 mode. It was plausible to guess that ATLAS might have observed the J 1 0 ( Determination of the weak isospin of the → 7 MeV in the ± ∗ c ]. pp ≈ ¯ c B ± b 35 β ψ π ]. In 2006, the CDF Collaboration reported the definitive observation of time- mixing, fixing the (very rapid) oscillation frequency at → ] in / ) J 0 s 31 and 39 ¯ ], within one standard deviation of the current world average. Five years later, CDF S B , Figure 8: 2 - s ( 0 s 32 ] (sin2 family of mesons has attracted theoretical interest for decades because of its intermedi- ∗ c [ B c 017 [ B 1 29 → . B − 0 c collaboration in 2 fb ps , ± c b ¯ h Until recently, the only evidence reported for a The Expectations of appreciable → 699 07 . . all excited states cascade to the ground state. The prediction from lattice QCD [ b penguin diagrams [ into two- or three-gluon intermediate states that characterize Collaboration was able to announceThe the long reconstruction wait of meant that the reconstructed mass, Collaboration [ reported the first detection of have now been observed in dozens of decay0 modes, and the mixing parameter has settleddependent to sin2 experimentation—in dialogue with theory—we now have atests library of of the highly Cabibbo–Kobayashi–Maskawa constraining quark-mixing precision paradigm [ 3. Mesons with Beauty and Charm ate position between the a new state at 6842 Beauty 2019 Opening BABAR [ 0 sensitive to relativistic effects [ detected in the transition decay, and that the signal is an unresolved combination of 2 LHC PoS(Beauty2019)001 , )] c col- B ]). ( levels pp 41 S M ]. These 2 GeV is . − 43 Chris Quigg ) [ levels might ∗ c b 31 MeV. The B ¯ b ( c − levels in , M [ b c B , sets the splitting between )] c B ]. The spectrum shown in Fig- ( 41 M 29 MeV and LHC − ) − ∗ c ]). B ( levels, in the form of well-separated peaks 37 ) M [ S spectrum [ 2 c − ( c B )] B 7 0 c candidates. The broad enhancement below 6 B spectrum ± ( c M B ψπ / − J ) ∗0 c mesons (from Ref. [ B ( c B M [ ] beat us to the arXiv, followed not long after by LHC ≡ 42 21 ∆ 23 MeV, whereas CMS measures

6800 6600 6400 7000 6200

spectrum, with (spin-singlet, spin-triplet) states on the (left [red], right [blue]) for 7400 7200 7600 − Mass [MeV] Mass ¯ b c invariant mass distribution, closely matching the theoretical template. The differ- − π Calculated + Invariant mass distribution of the π c B , calculated in a nonrelativistic potential model, indicates that 12–15 narrow The CMS Collaboration [ The unsettled experimental situation and the advent of large new data sets motivated us to 10 and explored how higher levels might be observed. experiments published striking evidence for both for which we assumed 54 MeV, the consensus value of modern lattice QCD calculations. We look Figure 10: each orbital-angular-momentum family; dashed lines mark two-body open-flavor thresholds (Ref. [ in the ure be found. We calculated hadronic and electromagnetic cascade decay rates for the expected narrow states, and computed differential andlisions integrated at cross the sections LHC. for Putting the all narrow these elements together, we discussed how to unravel the 2 ence of mass differences, the peaks. We estimate estimate depends on the not-yet-measured hyperfine splitting of the ground state, Figure 9: take a new look at the prospects for filling in the Beauty 2019 Opening attributable to partially reconstructed PoS(Beauty2019)001 ) ¯ D D 3621 ) since → ( ) ) S state can 2 D ++ cc ( 0 c 3 Chris Quigg final states. Ξ S ( 1 B 3 , D 35 MeV. We . ∗ invariant mass ψ ) 0 B S ] (left panel) and − ≡ 2 ± ( π 3 42 ∗ c + and D B 51 line near open-flavor 3 π . ]. In the heavy-quark 0 BD 48 BD ± 79 . 2 -wave) = line is favored for its high photon d ) Γ , is to be found above flavor threshold, 4 F 3 mesons must exist. To apply this insight, 777 MeV ( l ¯ γ q ∗ c k ¯ q B ] for the charmonium level 3 j 8 Q 44 → i mass spectrum up through 7200 MeV for indications ) Q level has decays into both the transition goes undetected. − levels will lie above flavor threshold. The 3 1 lines. π γ S S 7154 + 3 − ]. The discovery of the doubly-charmed baryon cascades. A particularly attractive target for experiment is ( π ) + 2 π c ) S 46 P + ¯ b 3 B 1 candidate [ ( c 12 MeV and natural width π . c ( ∗ c b 0 B B spectroscopy. ± invariant mass distributions reported by the CMS [ and the 3 → c ] has provoked a new wave of interest in exotic mesons containing → ) ]. B − D 1 16 S ∗ 47 . π S 1 45 3 B 0 ( + ∗ c π line, because of the favorable production cross section, branching fraction, ± B c γ B ∗ c 72 and 3 state might be observed as a very narrow ( . B ) − ¯ b π → c + ( 3842 ) experiment [ π 2 c (Shifted) b = P 3 B ] (right panel) Collaborations. The (lower, upper) peak is interpreted as ( 6750 M ( → 43 2 [ 0 P 3 S The proposition that stable or nearly stable multiquark states containing heavy flavors might It may in time become possible for experiments to detect some of the more energetic E1- Our calculations indicate that the 3 The 3 b 1 forward to further experimental analysis tocan determine test the relative calculations weights of of the production two and peaks, which decay rates, and to studies of the perhaps near 4054 MeV [ exist goes back nearly four decades [ we take into account corrections for finite heavy-quark masses to deduce which tetraquark states and 409-MeV photon energy. The 3 4. Tetraquarks stable against strong decays the photon energy in the decay into the final state at mass anticipate that one more narrow charmonium state, 4 energy, which may be a decisive advantage for detection. two heavy quarks. Estia Eichtenconfigurations and I for have which examined all the possibility stronglimit, of decays stable—hence unconventional are tetraquark exceedingly kinematically narrow— forbidden [ transition photons that appear in the 2 LHC distribution as next steps in However, it is conceivable that coupled-channel effects mightIt push one is or therefore both worth states lower examining in the of mass. 3 in the LHC Figure 11: Beauty 2019 Opening threshold, in the spirit of the LHC PoS(Beauty2019)001 (4.1) . This diquark 1 , where . In that isoscalar ) ) configura- 12 M + Chris Quigg motion and ¯q / 1 6 QQ ¯q 1 ( Q . Using a half- ( = O 12 P J in a color- + interaction, altering Q Q ) j M ¯ Q Q . )] i ) Q value for the decay is 2 ( Q v m mesons must exist. ( ¯ q l Q x ¯ O q k Q ¯ ( state into a pair of heavy–light + q ¯q j is the strong coupling. For large ) m 1 ¯q l [ s Q ¯ i 2 q − α ) k s ¯ ) q l α j diquark is a color-antitriplet, heavy- 2 3 q k ) ( Q i 2 1 q , and j x Q (QQ) ( QQ tetraquark meson is stable against strong − Q Q ( ( ) l l ¯ q m q k , and ¯ q k i j q ) = 9 Q ( Q m i ∆ q Q j state as the heavy-quark masses decrease (and the mean ¯q l configuration and repulsive for the color- Q ¯ i q ¯q k , a ¯ )] = 3 ¯ Q l q j ( Q ¯ q j m Q i Q ? For very heavy quarks, the contributions of Q − ( ) ) (QQ) m m l ¯ ¯ q q l k ¯ q ¯ in a color- q ) + k j ¯ k attraction is half that of the corresponding q ) ¯ q Q i i ¯ 3 is the reduced mass of Q Q . QQ ( ( 1 ( ) + ( − }− m m m [ ) ] q ¯ j ¯q bb j d , the middle term on the right-hand side dominates, so the tetraquark is stable ¯ { linear quarkonium potential, we verified that the rms core radii are small on the u − Q [ ¯q Q diquark as a tiny, structureless, color-antitriplet color source. As the separation quarks might be stable. The most promising candidate is a ) + i M m T l ) c ¯ / Q q ( k 1 ¯ q , so no decay to a doubly heavy baryon and a light antibaryon is kinematically al- or QQ j + p ( → i (QQ) Schematic evolution of a b Q Q i ) l meson, ¯ , the contribution due to light dynamics, becomes independent of the heavy-quark masses, m Q q mix, and eventually leading to the fission of the ) b ( With no open channels in the heavy-quark limit, stable Q k / l ¯ q 1 6 m q j ( , , To assess the implications for the real world, we must first test whether it makes sense to What of the other possible decay channel, a doubly heavy baryon plus a light antibaryon, Let us start with the observation that one-gluon-exchange between a pair of color-triplet heavy ¯ k 3 Q ≡ i ≡ q ( Q mesons. These changes are indicated in thestrength progression Coulomb from left to right in Figure idealize the between the heavy quarks increases, the light-antiquark cloud screens the ∆ enough values of spin to the tetraquarkquark mass symmetry are tells negligible. us that Since the Taking into account finite-mass corrections prescribed bysured heavy-quark masses symmetry, to we show can that use the mea- antibaryon, right-hand side ¯ is in everylowed. case smaller than the mass of the lightest the against decay into two heavy-light mesons. ( M as a stationary, structureless color charge, as depicted in the leftmost panel in Figure Figure 12: double- tion. The strength ofmeans the that in the limit of very heavy quarks, we may idealize the color-antitriplet quarks is attractive for Beauty 2019 Opening containing separation between the heavy quarks increases) from left to right. case, we can separateaction the by strong which dynamics the bindingcleus.” light the antiquarks diquark For interact from with sufficiently the each heavy long-range other color quarks and inter- are bound to the diquark “nu- Q decays, as we cantion into show two by heavy–light considering mesons possible is decay kinematically modes. forbidden. First, The we note that dissocia- PoS(Beauty2019)001 , ] ¯ q ¯ ). + s − cc ¯ ∗ s → d Q ¯ Σ [ D − 4.1 } color ) + 0 bc + and r ¯ ), with q Ξ meson, bb D Q ] { Q ¯ q bc 1 ps. 4.1 d ]. → → . None of ¯ Q Chris Quigg u 10482 [ ) ∼ p + − ( 50 } and ) ) } Q ]. ] ] ¯ bb d ¯ bb s ¯ { u ¯ 53 { [ 4156 u [ ( 3978 in the heavy-quark T diquarks as hadron } ( 10643 , can be considered ) } . This assessment is ( ¯ ++ 3 n ] . ) ¯ bb } j 2, but a } cc d ¯ { { ++ cc Q ] ] u ¯ ¯ ¯ bb cc [ cc s s Q ¯ = ¯ { m { Ξ u j ( d [ [ T Q B Q T T i + )( ¯ l Q + i ) masses. 1 Q 28 fm ¯ q . Q k core excitations. ] and SELEX [ q = Q ) ; 0 52 P , and 1 [ ) )( j J 0 QQ b ) bc (and ¯ ( Q ( i Q might be seen as “wrong-sign” ( QQ 7229 l ]). level. Other promising cases include the ( ¯ q ] ] k ¯ 24 fm 54 ¯ d ¯ q . bc q ¯ [ u q [ cc ; 0 T ) 10 + between LHC bb and ( + cc , 0 l ¯ 0 Ξ q ) k ¯ q combinations near threshold. (In their model calculations, 19 fm . bc 7272 0 BB ( , } = ] (which establishes a weak decay), ¯ bc d 2 ¯ { DB u / ¯ [ ]. ν , 1 i − T , and so on. Observing a weakly decaying double-beauty state would 49 2 ` ) r DD + + 0 h ¯ Σ D , , 1 ] estimate somewhat deeper binding, and so point to additional − ¯ Λ B ( −− 51 , states, as well as 0 bc − , l Ξ 0 ¯ q ) k , and ¯ tetraquarks to lie at least 78 MeV above the corresponding thresholds for strong → q − l 0 ¯ ) q bb π k + ¯ 10681 q j ( D } l } bound by 121 MeV against strong decays, and the axial vector Q ¯ − q i 10643 k bb B ¯ ( q limit? This is an example of a six-quark state with baryon number structure, if the three-diquark configuration should dominate. Look for double-flavor resonances near threshold. Measure cross sections for final statesDiscover containing and 4 determine heavies: masses ofplement doubly-heavy the baryons. heavy-quark-symmetry calculation We of need tetraquark masses this embodied information in to Eqn. ( im- Does it make sense to consider body plans such as Find stable tetraquarks through weak decays. A rough guess for the lifetimes is The doubly heavy baryons are also ofble intrinsic heavy–light interest: mesons, in with the the heavy-quark added limit, possibility they of resem- Refine lifetime estimates for stable states. Understand how color configurations evolve with Resolve the uncertainty surrounding Develop expectations for production (cf. Ref. [ { Q { } }− , Heavier The essence of the problem is easy to state, but not so easy to answer: What makes an electron We find two real-world candidates for stable tetraquarks: the axial vector If we had access to measured masses for all of the doubly heavy baryons, Eqn. ( ] ] ¯ ¯ p ¯ T bb bb s d 1. 2. 9. 5. 7. 8. 4. 6. 3. ¯ ¯ { { d u [ [ 0 bc + T T T T T T T T T Karliner and Rosner [ resonances in double-flavor T constituents. establish the existence of tetraquarks and illuminate the role of heavy color- an electron, a top quark a top quark, a neutrino a neutrino? We do not have a clear view of how to Ξ 5. Flavor: the problem of identity this will be easy, but both experiment and theory have much to do along the way. decay. Promising final states in which to search for stable tetraquarks include consistent with other results [ T mesons bound by 48 MeV.other Given the provisional doubly heavy baryon masses, we expect all the controlled finite-mass corrections, wouldtervention yield of predictions any of models. tetraquark masses, That without is the not in- yet the case; only one example, Beauty 2019 Opening expected tetraquark scale: established. While waiting for experiments toinputs provide the more model comprehensive calculations information, of we use doubly-heavy baryon as masses by Karliner & Rosner [ candidates.) For example, the double-charge, double charm would constitute prima facie evidence for a non- 1 PoS(Beauty2019)001 Chris Quigg ? Z and ± measured in inclusive and exclusive W they have the values we observe. In | cb V | why and ? ) | . ¯ ; 2 Parameters of the Higgs potential; 1 Vacuum − ν ub ν W µ V 11 seemingly arbitrary parameters. Of these, twenty | θ + + 2 π + µ → → , sin s + em B K ( α , B s and α anything at all? Contrast the landscape perspective. − µ ), and + ¯ ν mean µ ν + → π d , s → B + K 3 (CKM) quark-mixing matrix unitary? ( ]. They arise generically in proposals for physics beyond the standard model, and × B 55 , γ Have we found the “periodic table”What of do elementary generations particles? mean? Is thereWhy a are family there symmetry? three families ofAre quarks there and new leptons? species (Is of it quarksIs so?) and there leptons, any possibly link carrying to exotic a charges? What dark will sector? resolve the disparate values of need to be controlled. Andon yet studies we of have made no sightings! Why not? The focus for now is How well can we test the standard-modeleter correlation among the quark-mixing matrix param- decays? Is the 3 Why is isospin a good symmetry?Can What we does find it evidence mean? for charged-leptonWill flavor we violation establish in and lepton diagnose decays? aDo break flavor in parameters the standard model? What is the relationship of left-handedAre and there right-handed additional fermions? electroweak gauge bosons,Are beyond there additional kinds of matter? Is charged-current universality exact? What aboutWhere lepton-flavor are universality? flavor-changing neutral currents in quarkare transitions? absent In the at standard tree model, these nism level [ and highly suppressed by the Glashow–Iliopoulos–Maiani mecha- If flavor parameters havequestion? meaning (beyond engineering information), what is the meta- Can we find evidence of right-handeddamentally charged-current asymmetrical interactions? plan, Is or nature are builtfor on the us a right-handed to fun- have weak observed interactions until simply now, reflecting too an feeble underlying hidden symmetry? masses and mixing angles arise, we do not know Our ability to calculate within the standard model rests on knowing the values of many pa- F8. F9. F7. F2. F3. F4. F5. F6. F1. F10. F11. F12. F13. F14. F15. F16. F17. F18. F19. phase (QCD); 6 Quark masses,masses, 3 3 Quark Neutrino mixing masses, angles,plus 3 1 Leptonic two CP-violating Majorana mixing phase; phases), angles, 3 for 1concern the Charged-lepton Leptonic a flavor CP-violating total sector. The phase of problem (probably 26 of identity is rich in questions: rameters: 3 Coupling parameters, Beauty 2019 Opening approach the diverse character of the constituentsily of fruitful matter. The framework CKM in paradigm the is hadrondetermines an extraordinar- sector, them, but nor there are at manyhow what parameters. energy We scale have no they cluethis are what sense, set. all fermion Even masses—beginning with ifstandard the model! the electron Higgs mass—cry out mechanism for explains physics beyond the PoS(Beauty2019)001 , which − e Chris Quigg as expected + e Z → and H W ]? ? make top an outlier or ? ) t t act as a portal to hidden 56 ? ) ) m u 125 , ( c 125 H ( )( γ test the electroweak-theory pre- H ? What about , ¯ t c Z c ( m ? → → ]? How free is ts t and V H 57 W ]. M and 59 , . . . )? td V ∓ production in QCD: total and differential cross constraints? µ ¯ 12 t t H ± τ M - W ) occur at standard-model rates? ? Z M H - γ t Γ , in single-top production, and elsewhere? m dynamics? Does the large value of γγ ¯ tb t , t V gg resonances? soon? How can we detect ¯ t t − µ (Yukawa) coupling imply a special role in electroweak symmetry break- ¯ + t µ Ht ? fully account for electroweak symmetry breaking? Does it match standard- H ) M ]. We can summarize by saying that the evidence is developing as it would if the only member of its clan? Might there be others—charged or neutral—at higher matches the textbook Higgs boson [ ) 125 58 ) ( were the textbook scalar responsible for electroweak symmetry breaking and the H ) 125 125 ( ( H H Is model branching fractions to gauge bosons? Are absolute couplings to How well can we constrain theAre top-quark there lifetime (vestiges [ of) Can we find evidence of flavor-changing top decays or lower masses? Does diction for in the standard model? Are all production rates as expected?What Any accounts surprise for sources the of immense rangeIs of the fermion Higgs masses? field the onlyfermion source masses? of fermion masses? Are fermion couplings proportional to How much can we tighten the How stringently will refined measurements of Does top’s large ing? How does it influence the only normal fermion? How well can we constrain How much can we refine our knowledge of sections, charge asymmetry, spin correlations, etc.? What might we learn from “dead-cone” studies using boosted tops [ would give new insightbonding? into the finiteness ofWhat role the does Bohr the Higgs radius fieldCan play and we in establish the generating or neutrino origins exclude masses? decays of to valence new particles? Does How complete is our understanding of sectors? When can we measure Can we detect flavor-violating decays ( Do loop-induced decays ( In a few short years, the LHC experiments have given us a wealth of information about the The top quark touches many topics in particle physics and presents us with many questions. 1. 8. 9. 2. 3. 4. 5. 2. 1. 3. 4. 5. 7. 6. 7. 6. 8. 9. 125 GeV t t t t t t t t t 10. ( H H H H H H H H H t Higgs boson [ 7. Electroweak symmetry breaking and the Higgs sector H generation of fermion massesmetry and breaking mixings. and the Here Higgsclosely is sector a that list we of must answer questions to about approach electroweak a sym- final verdict about how Beauty 2019 Opening 6. Top matters PoS(Beauty2019)001 ], 61 assess you Chris Quigg ] and series of seminars [ 60 , . . . )? γ ϒ , of 13 regulates Higgs–Goldstone scattering, i.e., tames the ψ γ / J H scattering? trilinear self-coupling? WW HHH Collider (FCC-hh or SppC)? Higgs factory? for Beauty and in general H pp → − µ + µ (a) The High-Luminosity LHC? (b) The High-Energy LHC? (c) A 100-TeV (d) A 250-GeV ILC? (e) A circular Higgs factory (FCC-ee(f) or A CEPC)? 380-GeV CLIC? (g) A (h) LHeC / FCC-eh? (or an(i) electron–ion A collider?) muon-storage-ring neutrino factory? (j) A multi-TeV muon collider? (k) The instrument of your dreams? high-energy behavior of What can we learn from rareDoes decays the ( electroweak vacuum seem stable,Can or we suggest find a signs new of physics new scale? Can strong we dynamics establish or the (partial) compositeness? How well can we test the notion that Is the electroweak phase transition first-order? I thank the Beauty2019 Organizing Committee, particularly Robert Fleischer and Guy Wilkin- This work was supported by Fermi Research Alliance, LLC under Contract No. DE-AC02- Our experimental future demands both diversity and scale diversity, but an important driver 10. 11. 12. 13. 14. 15. H H H H H H the scientific potential Acknowledgments son, for their kind invitation toled present the by opening Bostjan lecture. Golob, for Congratulations their toin flawless our looking preparations Ljubljana forward and hosts, to peerless Beauty2020, hospitality. where I we join anticipate all the participants first wave of07CH11359 results with the from U.S. Belle Department II. of Energy, Officeand of Science, by Office of the High Energy Munich Physics, Deutsche Institute Forschungsgemeinschaft (DFG, for German Astro- Research Foundation)lence and under Strategy Germany’s Particle Excel- – Physics EXC-2094 (MIAPP), –Bavarian 390783311. which State I is Ministry am for funded grateful Science,Study by to at Research, the the Technical and University Visiting Munich the Professor where Program Arts muchfor of of a and this the long also talk and the was enlightening prepared. collaboration. Institute I for thank Advanced Estia Eichten where you may find pointers to detailed information. Now, the great question: How do of progress will bepossibilities, the form an next opinion, great and communicate accelerator. itI to have our Every colleagues given one in an particle of inventory physics of and us beyond. frontier should machines take in time a recent to essay explore [ the Beauty 2019 Opening 8. Future instruments PoS(Beauty2019)001 17 . 44 , . . Rev. ; − 39 e et al. + e Courier Chris Quigg (1974) in G. Ekspong (1978) 462 33 Phys. Rev. Lett. CERN Courier (1977) 286 (1978) 391 NAL Proposal CERN . For additional 72B (1977) 1240 Phys. Rev. Lett. 66B 39 Phys. Rev. Lett. 780823 , “The Discovery of a Annihilation,” Phys. Lett. et al. (1974) 1453 Phys. Rev. Lett. − e Phys. Lett. 33 ,” Particle: A Personal Recollection,” + J e J at the Cornell Electron Storage Ring,” . See in particular R. K. Ellis Phys. Rev. Lett. High energy physics. Proceedings, 19th Conf. Proc. C 00 ϒ and , 0 Region,” Annihilation,” ϒ Anomaly in Inelastic anti-neutrino Scattering,” , ϒ − Phys. Rev. Lett. e y ϒ Number 1–2 (1977) 3–5. + pp. 391–408: e 14 . See also G. S. Abrams 17 . (World Scientific, Singapore, 1997), pp. 168–195. . Leon Lederman’s announcement at the 1977 European . Courier “Reflections on the Discovery of the Tau Lepton,” Anomaly in anti-neutrino Interactions?” Annihilation,” . y (1974) 1406 − . e , “Observation of (1977) 252 . . + . 33 e CERN (1977) 1640] 39 et al. 39 . (1976) 70 14 (1973) 652 , “Further Data on the High [SLAC-SP-017 Collaboration], “Discovery of a Narrow Resonance in (1977) 235 (1980) 1111 (1976) 1478 49 [CLEO Collaboration], “Observation of Three Upsilon States,” “A Study of Di-Lepton Production in Proton Collisions at NAL,” . , “Observation of Structure in the 49 , , “Experimental Observation of a Heavy Particle et al. , “Observation of a Dimuon Resonance at 9.5-GeV in 400-GeV Proton-Nucleus 44 36 , “Is There a High , “Evidence for Anomalous Lepton Production in . See also M. L. Perl, (1977) 251 Phys. Rev. Lett. et al. et al. et al. Phys. Rev. Lett. ; T. Bohringer 49 et al. et al. et al. . et al. et al. [Phys. Rev. Lett. Phys. Rev. D Nobel lectures in physics 1991-1995 . For a perspective, see S. C. C. Ting, “The Discovery of the number 7–8 (July–August 1977) 223 (1975) 1489 Annihilation,” Second Narrow Resonance in perspective, consult B. Richter, “From the psi to Charm: The Experiments of 1975 and 1976,” Theoretical,” in S. Homma, M. Kawaguchi and H. Miyazawa, (1980) 1108 Phys. Rev. Lett. Phys. Rev. Lett. International Conference, ICHEP 1978, Tokyo, Prog. Theor. Phys. Quarks,” Erratum: Mod. Phys. 35 (ed.), (1977) 433 Rev. Mod. Phys. Collisions,” “Physics Briefing Book : Input forarXiv:1910.11775 the European Strategy for Particle Physics Update 2020,” Physical Society conference in Budapest is17 recounted in “The discovery of Upsilon,” #288 (February 1974). For color commentary,Number see 1–2 T. (1977) Toohig, “Leon 25. and the Lady,” https://europeanstrategyupdate.web.cern.ch 1404 [8] “FERMILAB Dileptomania,” [9] M. Kobayashi and T. Maskawa, “CP Violation in the Renormalizable Theory of Weak Interaction,” [7] M. L. Perl [4] J. A. Appel [6] J. E. Augustin [2] S. W. Herb [5] J. J. Aubert [1] Information about the European Strategy for Particle Physics may be found at [3] W. R. Innes [15] See the discussion surrounding Figure 3 of J. D. Jackson, C. Quigg and J. L. Rosner, “New Particles, [12] A. C. Benvenuti [16] D. Andrews [10] E. Eichten and K. Gottfried, “Heavy Quarks in [13] R. M. Barnett, “Evidence in Neutrino Scattering for Righthanded Currents Associated[14] with Heavy M. Holder [11] C. Quigg and J. L. Rosner, “Counting Narrow Levels of Quarkonium,” Beauty 2019 Opening References PoS(Beauty2019)001 . . 81 97 Phys. ]. 45 M. Bona Phys. 192 (1983) (2011) ,” Chris Quigg (2018) (1992) 3262 ) Nucl. Phys. Flavored S 51 meson 4 B 98 45 106 ( B (1983) 1022 (1987) 565 ϒ -lepton properties 51 τ Phys. Rev. Lett. Rev. Mod. Phys. 197 [ ]; T. Maskawa, “Nobel Decays,” meson system,” Phys. Rev. Lett. (2006) 081 Phys. Lett. B 0 B B Phys. Rev. D Phys. Rev. D 0610 (2005) 1 UTfit Collaboration: Phys. Rev. Lett. Phys. Rev. Lett. 41 Mesons,” -hadron, and Mixing,” ]. c (2009) 1019 Oscillations,” 0 B (2009) 2393 Phys. Lett. B JHEP ¯ Phys. Rev. Lett. B 0 s , “CP violation and the CKM matrix: ¯ 81 ,” quarks,” - B 24 ) 0 b τ − B 0 s τν et al. Oscillations at the CERN Proton - -hadron, B b 0 Quarks,” → ¯ B ]. , Erratum: [ B B - Eur. Phys. J. C ( 0 ]. B B J. Charles 15 Rev. Mod. Phys. and [ s arXiv:hep-ex/0107061 [ (1987) 247 m Int. J. Mod. Phys. A factories,” ∆ . B 186 ]. arXiv:1708.04012 [ (2009) 2379 . (1983) 881 24 CKMfitter Group: arXiv:hep-ex/0107013 [ (2001) 091802 50 87 Phys. Lett. B ]; and ]. For perspective, see M. Kobayashi, “Nobel Lecture: CP violation and flavor . (2018) 015003 [Particle Data Group], “Review of Particle Physics,” [CDF Collaboration], “Observation of , “Lifetime of Particles Containing [CLEO Collaboration], “Observation of Exclusive Decay Modes of [HFLAV Collaboration], “Averages of [ARGUS Collaboration], “Observation of [CDF Collaboration], “Measurements of Direct CP Violating Asymmetries in 90 , “Measurement of the Lifetime of Bottom Hadrons,” [UA1 Collaboration], “Search for . arXiv:hep-ex/0609040 [BaBar Collaboration], “Observation of CP violation in the [CLEO Collaboration], “Evidence for New Flavor Production at the [ et al. et al. et al. [Belle Collaboration], “Observation of large CP violation in the neutral (2001) 091801 (1981) 84 et al. et al. arXiv:1909.12524 et al. et al. et al. et al. . ; Phys. Rev. Lett. et al. 87 46 et al. Int. J. Mod. Phys. A Phys. Rev. Lett. [arxiv:1103.5762]. et al. , and 2019 update. (1981) 85 . , “The Unitarity Triangle Fit in the Standard Model and Hadronic Parameters from Lattice QCD: 193 arXiv:hep-ph/0606167 arXiv:hep-ph/0406184 as of 2018,” anti-Proton Collider. 2.,” (1987) 245 Rev. Lett. 181802 et al. A Reappraisal after the Measurements of Assessing the impact of the asymmetric mixing,” Lecture: What does CP violation tell us?” [ [ Charmless Decays of Strange Bottom Mesons and Bottom Baryons,” B system,” (2006) 242003 Rev. Lett. Rev. Mod. Phys. (1980) 952 Mesons,” 030001 1316 T. Skwarnicki and D. Zieminska, “Nonstandard heavy mesons and baryons: Experimental evidence,” [27] H. Albrecht [29] B. Aubert [30] K. Abe [31] Y. S. Amhis [34] For recent compilations and critical evaluations, see the websites of the [24] E. Fernandez [32] A. Abulencia [33] T. Aaltonen [28] D. Schaile and P. M. Zerwas, “Measuring the weak isospin of [20] A. B. Carter and A. I. Sanda, “CP Violation in Cascade Decays of [23] M. Tanabashi [25] N. Lockyer [26] C. Albajar [21] I. I. Y. Bigi and A. I. Sanda, “Notes on the Observability[22] of CPS. Violations Behrends in Beauty 2019 Opening [17] C. Bebek [18] Estia J. Eichten, private communication. [19] For a recent review containing extensive lists of nonstandard hadron candidates, see S. L. Olsen, PoS(Beauty2019)001 ]. 2 Phys. / (2019) c ]. 1 B edited by = 122 ]; and I Chris Quigg Phys. Rev. ∆ (2018) 46 Phys. Rev. ± ]. Phys. Rev. D ,” 97 ψπ . The origin of the / (2018) 233 ++ cc J Ξ ]. (2018) 138 → arXiv:1710.03236 778 [ ± c States and Measurement B (2019) 132001 + c 1801 Phys. Rev. Lett. B (1977) 316 Phys. Rev. C arXiv:hep-lat/0411027 122 [ Meson State with the ATLAS ]. 120 JHEP ± c state,” B Phys. Lett. B + c ] arXiv:hep-ph/9510397 ]. B (2006) 082002 (2018) 054505 ]. states,” 96 97 + c arXiv:hep-ph/0401210 spectroscopy and observation of a new [ B . ¯ (2005) 172001 D Phys. Rev. Lett. Nucl. Phys. B D 94 arXiv:1707.0957 [ arXiv:1407.1032 [ 16 Phys. Rev. D arXiv:hep-ph/9402210 13 TeV,” [ ]. arXiv:1903.12240 Phys. Rev. Lett. ]. [ = (2004) 094019 s (2019) 012039 ITEP Lectures in Particle Physics and Field Theory, √ 69 Phys. Rev. Lett. 1137 meson,” c (2017) 202002 B (1994) 5845 (2019) 035 (2014) 212004 49 119 ]. ]. 113 arXiv:1902.09735 Collisions at 1907 [ arXiv:1707.01621 Phys. Rev. D [ ]. pp ,” [CMS Collaboration], “Observation of Two Excited ψ JHEP / [CDF Collaboration], “Evidence for the exclusive decay . ]; C. Hughes, E. Eichten and C. T. H. Davies, “Searching for beauty-fully bound ]. ]. J [HPQCD and Fermilab Lattice and UKQCD Collaborations], “Mass of the − J. Phys. Conf. Ser. et al. Phys. Rev. D π . An exemplary bibliography appears in J. M. Richard, A. Valcarce and J. Vijande, Mass in et al. + [LHCb Collaboration], “Near-threshold [LHCb Collaboration], “Observation of the doubly charmed baryon [LHCb Collaboration], “Search for excited [ATLAS Collaboration], “Observation of an Excited [LHCb Collaboration], “Observation of an excited ) et al. π ]. And keep in mind N. Cabibbo, “Unitary Symmetry and Leptonic Decays,” S Phys. Rev. Lett. Phys. Rev. Lett. (2019) 054025 2 (2017) 112001 ( ,” → arXiv:1904.00081 arXiv:1803.06155 l (1963) 531 [ [ + c et al. et al. et al. et al. ¯ et al. ) 99 q k B ¯ 119 10 q j (1982) 2370 3872 Q i ( arXiv:1708.04594 arXiv:1902.00571 arXiv:1712.04094 arXiv:hep-ex/0505076 035211 measurement of the mass of the meson in three-flavor lattice QCD,” P. Bicudo, M. Cardoso, A. Peters,in M. lattice Pflaumer QCD,” and M. Wagner, “Doubly heavy tetraquark resonances charmonium state,” M. Shifman (World Scientific, Singapore, 1999) Vol. 1, pp. v–xi [ 232001 25 Lett. A. Czarnecki, B. Leng and M. B. Voloshin, “Stability of tetrons,” tetraquarks using lattice nonrelativistic QCD,” Q [ penguin monicker is the stuff ofto legend, ITEP recounted lectures (for in example) particle in physics,” §1.1 in of M. A. Shifman, “Foreword of the [ “Few-body quark dynamics for doubly heavy baryons and tetraquarks,” Spectroscopy,” [ X [ Lett. Rev. D (2009) 1027 Rule in the Nonleptonic Decays of Strange Particles,” Detector,” [46] J. P. Ader, J. M. Richard and P. Taxil, “Do Narrow Heavy Multi - Quark States Exist?,” [48] E. J. Eichten and C. Quigg, “Heavy-quark symmetry implies stable heavy tetraquark mesons [42] A. M. Sirunyan [44] R. Aaij [47] R. Aaij [41] E. J. Eichten and C. Quigg, “Mesons with Beauty and Charm: New Horizons in Spectroscopy,” [43] R. Aaij [36] My own interest dates back to E. J. Eichten and C. Quigg, “Mesons with beauty and charm: [45] E. J. Eichten, K. Lane and C. Quigg, “Charmonium levels near threshold and the narrow state [49] For investigations using a variety of techniques, see Richard–Valcarce–Vijande, in Ref. [ [38] I. F. Allison Beauty 2019 Opening [35] M. A. Shifman, A. I. Vainshtein and V. I. Zakharov, “Light Quarks and the Origin of the [37] A. Abulencia [39] G. Aad [40] R. Aaij PoS(Beauty2019)001 ,” + cc ) ¯ Ξ d ¯ u bb Chris Quigg ]. Sci. China Phys. (2016) 054015 ]. ,” 94 + cc Ξ “CMS Higgs Physics Results.” ]. arXiv:1808.06036 [ Phys. Rev. D baryon implies a stable ( cc arXiv:1805.02535 [ , see The ATLAS Collaboration website, Ξ ]. ) ]. 125 (2019) 3 13 TeV with the ATLAS detector,” ; F. Maltoni, M. Selvaggi and J. Thaler, ( ]. H = 10 ]. s (2018) 412 √ arXiv:1707.07666 [ 17 782 5 GeV, to be compared with the standard-model arXiv:1408.5877 . (1991) 1602 [ ]. 0 Yale University Nuclear/Particle/Astrophysics Seminar 17 ± 9 . 1 arXiv:1808.01324 arXiv:hep-ex/0208014 [ [ arXiv:1909.12273 [ (2017) 202001 ) = and The CMS Collaboration website, Phys. Lett. B t ( Rev. Accel. Sci. Tech. J. Phys. G Γ 119 (2014) 094007 . (2019) 1 zenodo.3663044 . 90 factory,” 816 Z (2002) 112001 ]. (2020) 221062 [SELEX Collaboration], “First Observation of the Doubly Charmed Baryon 32 GeV. See The ATLAS collaboration, “Measurement of the top-quark decay width 89 . (1970) 1285 63 2 [LHCb Collaboration], “Search for the doubly charmed baryon Phys. Rev. Lett. et al. Phys. Rev. D “Perspectives and Questions,” Phys. Rept. et al. arXiv:1606.03449 expectation of 1 in top-quark pair events in the dilepton channel at tetraquark,” “Exposing the dead cone effect with jet substructure techniques,” “Public Results: Higgs Physics” it’s over,” slides November 5, 2019 [ ATLAS-CONF-2019-038 Phys. Rev. D [ Phys. Rev. Lett. tetraquarks at a Tera- fragmentation (’dead cone’),” Mech. Astron. detection,” [60] C. Quigg, “Dream Machines,” [61] C. Quigg, [57] A recent measurement yields [58] For compilations of recent results on the Higgs boson [59] For an instructive narrative, see S. Dawson, C. Englert and T. Plehn, “Higgs Physics: It ain’t over till [51] M. Karliner and J. L. Rosner, “Discovery of doubly-charmed [53] M. Mattson [54] A. Ali, A. Y. Parkhomenko, Q. Qin and W. Wang, “Prospects of discovering stable double-heavy [56] Y. L. Dokshitzer, V. A. Khoze and S. I. Troian, “On specific QCD properties of heavy quark Beauty 2019 Opening [50] M. Karliner and J. L. Rosner, “Baryons with two heavy quarks: Masses, production, decays, and [52] R. Aaij [55] S. L. Glashow, J. Iliopoulos and L. Maiani, “Weak Interactions with Lepton-Hadron Symmetry,”