PRODUCTION AND SPECTROSCOPY OF OPEN-FLAVOURED HADRONS AT HADRON COLLIDERS

PRODUCTION AND SPECTROSCOPY OF OPEN-FLAVOURED HADRONS AT HADRON COLLIDERS Marco Pappagallo On behalf of the collaboration including results from CMS, ATLAS, ALICE and CDF Collaborations HADRON 3, Nara, Japan 4-8 November 3

OUTLINE Ø b and c-hadron production: ü Charm production ü Beauty production by partially reconstructed decays ü Beauty production by exclusively reconstructed decays Ø b and c-hadron spectroscopy: ü Excited D and B mesons ü Excited b baryons ü Search for doubly charmed baryon Ξ cc ü Precise mass measurements ü B c spectroscopy HADRON 3

b AND c-hadron PRODUCTION HADRON 3 3

MOTIVATION Ø Measurements of heavy quark production are important to test the accuracy of QCD predictions and to improve the knowledge of the ingredients which QCD predictions are based on (e.g. parton distribution functions, factorization and renormalization scales, fragmentation function, ) Ø Early measurements of bottom production at the Tevatron seemed to be significantly larger than QCD calculations. Since then, new frameworks have been developed to cope the discrepancies (e.g. FONLL, GMVFNS, POWHEG ) Ø It is crucial to test these frameworks at different energies and wide rapidity and transverse momentum ranges HADRON 3 4

PRODUCTION AT LHC Ø The LHC experiments cover different (and complementary) regions in rapidity (y) and transverse momentum (p T ) Ø Study of inclusive (e.g. J/ψ) production: ü Prompt : contribution produced directly in the proton-proton collision indirectly through the decay of heavier states (e.g. χ c à J/ψ γ) ü Non-prompt: contribution from long-lived hadrons (e.g. B à J/ψ K) Ø The differential cross section of (e.g.) Và μμ decay is computed as: d dydp T = N(V! µ µ ) L tot B(V! µ µ ) y p T HADRON 3 5

t 5 5 5 p t (GeV/c) t 5 5 5 p t (GeV/c) t 5 5 5 p t (GeV/c) PROMPT CHARM PRODUCTION AT S = 7 TEV Charm production measured by : D à Kπ, D à Kππ, D* à D π, D s à ϕ(kk)π, Λ c à pkπ [ NPB 87 (3) ] [ALICE PLB 78 () 79] [ALICE JHEP () 79] D D : <p T <8 GeV,. < y < 4.5 Ø log (IP χ ) used to account for charmed hadrons produced in b-hadron decays ALICE: < p T < 4 GeV, y <.5 Ø Fraction of D s coming from B mesons estimated from theory (IP used for cross-check) D * D s Differential cross-sections in agreement with theoretical prediction within uncertainties. Data are generally between the central values of FONLL and GMVFNS (µb/gev/c) d / dp Data FONLL Data GM-VFNS y <.5 3 - - 3.5 3.5.5.5 3.5.5 3.5 ± stat. unc. syst. unc. FONLL GM-VFNS 3.5% lumi, ± D, pp.3% BR norm. unc. (not shown) ALICE - s = 7 TeV, L = 5 nb int 5 5 5 p t GeV/c.5 5 5 5 p (GeV/c) t HADRON 3 (µb/gev/c) D D D * D s d / dp Data FONLL Data GM-VFNS y <.5 3 - - 3.5 3.5.5.5 3.5.5 3.5 ± stat. unc. syst. unc. FONLL GM-VFNS 3.5% lumi, ± D, pp.% BR norm. unc. (not shown) ALICE - s = 7 TeV, L = 5 nb int 5 5 5 p t GeV/c.5 5 5 5 p (GeV/c) t (µb/gev/c) d / dp Data FONLL Data GM-VFNS y <.5 3 - - 3.5 3.5.5.5 3.5.5 3.5 ± stat. unc. syst. unc. FONLL GM-VFNS 3.5% lumi, ± ALICE * - D, pp s = 7 TeV, L = 5 nb int.5% BR norm. unc. (not shown) 5 5 5 p t GeV/c.5 5 5 5 p (GeV/c) t Λ c 6

CHARM AND BOTTOM PRODUCTION USING ELECTRONS Ø Different sources of electrons discriminated by transverse impact parameter Ø e ± from b-hadrons Ø e ± from c-hadrons Ø e ± from photon conversion Ø e ± from Dalitz decays (e.g. π à γ e e - ) Ø Long lifetime of b-hadrons à Broad d distribution [ALICE PLB 7 (3) 3] 3 PYTHIA, s = 7 TeV, y <.8 <p <6 GeV/c T b ( c) e c e conversion elec. Dalitz elec. (a) Counts FONLL predictions in good agreement with data Data/MC 3.5.5.5 conversion electrons Data/MC <p < GeV/c T Data/MC <p <6 GeV/c T (b) -6-4 - 4 6 d (µm) HADRON 3 7

BOTTOM PRODUCTION USING DISPLACED J/ψ à µµ-, ee[ EPJC 7 () 645] [ JHEP (3) 4][ JHEP 6 (3) 64] [ATLAS NPB 85 () 387] [ALICE JHEP () 65] [CMS JHEP () ] Ø Bottom production measured at s = 7 TeV in different (pt, y) regions by LHC experiments Ø provides measurements at s =.76 and 8 TeV as well Ø bà J/psi X discriminated from prompt J/ψ by -D fit: MJ/ψ vs Pseudo-proper time: tz = Lz MJ/ pz ( only) or txy = Lxy MJ/ pt CMS s = 7 TeV L = 37 pb-. < y <.9 ( 65).9 < y <. ( 5). < y <.6 ( 5).6 < y <. ( 5). < y <.4 ( ) T B dσj/ψ/dp dy (nb/(gev/c)) non-prompt J/ψ µ µ-, corrected for acceptance FONLL FONLL predictions in good agreement with data - Luminosity uncertainty not shown 6 7 8 9 HADRON 3 3 4 5 pt (GeV/c) 8

BOTTOM PRODUCTION AT S = 7 TEV USING DISPLACED Ψ(S) à µµ-, J/ψππ[ATLAS CONF 3 94] [CMS JHEP () ] [ EPJC 7 () ] Ø Same technique as for J/ψ Ø ATLAS results overlaid to those from CMS and (N.B. Different rapidity ranges ) Some discrepancy between predictions and data at high pt. Tendency to underestimate data at low pt HADRON 3 9

BOTTOM PRODUCTION AT S = 7 TEV USING DISPLACED χ c Ø ATLAS measured bottom production using bà χ c X where χ c à J/ψ(μ μ - )γ(e e - ) Ø Converted photons used to resolve the χ c signals Ø -D fit to separate b-hadron component: Δm vs Pseudo-proper time Ø χ c signal is small for a reliable measurement Ø Results reported as function of p T (J/ψ) and p T (χ c ) [ATLAS CONF 3 95] χ c χ c χ c χ c General agreement though FONLL predictions slightly larger. Discrepancy maybe due to the use of the p ψ(s) for the χ c in the model HADRON 3

B PRODUCTION [ATLAS JHEP (3) 4] [CMS PRL 6 () ] Ø ATLAS measured B production using the B à J/ψK decay in the central region and in a wide pt range y <.5 ; 9 < pt < GeV Ø Data in agreement with CMS results and theoretical predictions HADRON 3

B( )() PRODUCTION AT S = 7 TEV S 6 5 4 4.5 < p < 5. GeV/c T 3. < y < 3.5 3 - s = 7 TeV 53 54 55 m ( J /ψ K ) [MeV/ c] Data Total Signal Background s = 7 TeV 4.5 < p < 5. GeV/ c T 3. < y < 3.5 5 5 dσ(b)/dp T [µb / (GeV/ c)] Candidates / ( 6 MeV/c ) 5 5 3 4 p (GeV/c) T (. < y < 4.5 ) BF uncertainty FONLL (. < y < 4.5 ) - s = 7 TeV - 5 (. < y < 4.5 ) BF uncertainty FONLL (. < y < 4.5 ) - 3 dσ(b)/dp T [µb / (GeV/ c)] s = 7 TeV 55 53 535 54 m ( J /ψ K * ) [MeV/ c] Data Total Signal Background s = 7 TeV 8 6 4. < p < 5. GeV/ c T 3. < y < 3.5 4 3 4 p (GeV/c) T (. < y < 4.5 ) BF uncertainty FONLL (. < y < 4.5 ) - - 5 HADRON 3 Data Total Signal Background B J /ψ π T Also CMS provided measurements of B production in the central region 7 dσ(bs )/dp [µb / (GeV/ c)] FONLL predictions in good agreement with data 8 Candidates / ( 5 MeV/c ) Ø measured B production by using: ü Bà J/ψ K ü Bà J/ψ K*(à Kπ-) ü Bsà J/ψ ϕ(à KK-) Ø Decay time >.3 ps to reduce combinatorial background Ø KK and Kπ S-wave components subtracted Candidates / ( 5 MeV/c ) [, JHEP 8 (3) 7] [CMS, PRL 6 () ] [CMS, PRL 6 () 5] [CMS, PRD 84 () 58] s = 7 TeV -3 53 54 55 m ( J /ψ φ ) [MeV/ c] 3 4 p (GeV/c) T

FRAGMENTATION FRACTION RATIO f s /f d [, JHEP 4 (3) ] [-CONF-3-] Ø f s /f d essential for measurements of B s branching fractions (e.g. B s à μ μ - ) Ø updated the measurement of f s /f d by using B à D - K and B s à D s - π ( fb - ) and the improved measurement of Br(D s à KKπ) Ø Evidence of dependence on p T (B), while no indication of dependence on η(b) d f.35 / s f d f.35 / s f.3.3.5.5. 3 4 p (B) [MeV/c] T. 3 4 5 η(b) f s f d =.59 ±.5 @ 7 TeV HADRON 3 3

Λb PRODUCTION AT S = 7 TEV [CMS, PLB 74 () 36] [, PRD 85 () 38] Ø : Measurement of fλb/fufd by studying semileptonic decay modes Bà DμνX and Λbà ΛcμνX. -D fit: m(d) or m(λc) vs IP Significant dependence of fλb/fufd upon pt(λcμ) HADRON 3 CMS s = 7 TeV L =.9 fb- Λb p > GeV T.4. -3.5.5 pt(λb) distribution falls faster than predicted by POWHEG b Data PYTHIA POWHEG POWHEG uncertainty - dσ/dy(pp Λ X J/ΨΛ X) (nb) CMS s = 7 TeV L =.9 fb- Λb y <. - Data PYTHIA POWHEG POWHEG uncertainty 3 4 Λ b 5 4 5 pt (GeV) 3 Λ p b (GeV) T data/powheg data/powheg dσ/dpt(pp ΛbX J/ΨΛ X) (nb/gev) Ø CMS: Measurements of Λb production in bins of pt and y by using an exclusive decay mode Λbà J/ψ(μμ-)Λ(pπ).5.5.5.5 Λ y b.5.5 Λ y b 4

Λ b POLARIZATION AT S = 7 TEV [, PLB 74 (3) 7] [ATLAS-CONF-3-7] Ø Longitudinal polarization vanishes due to parity conservation of strong interactions P k = h~ ~p b i = P b = P? = h~ ~p b ~p p i6= Ø Transverse polarization predicted to be as large as % (PLB 64 (5) 65) (N.B. Polarization << % expected by extrapolating the Λ polarization measured by fixed-target experiments) Ø Angular analysis of Λ b à Λ(pπ)J/ψ(μμ) to measure polarization and decay helicity amplitude The angular distribution depends on P b, α Λ, the 4 helicity amplitudes and 5 angles ü : Integration over two ϕ angles ü ATLAS: Detector symmetric in rapidityà P b = b M, M, M, M, P -violating asymmetry of the b! J/ decay HADRON 3 5

Λ b POLARIZATION AT S = 7 TEV [, PLB 74 (3) 7] Variable ATLAS P b.6 ±.7 ±..(fixed) b.5 ±.7 ±.7.8 ±.6 ±.6 M /,. ±.4 ±.3.7..7 ±.6 M /,.57 ±.6 ±.3.59.6.7 ±.4 M /,.5 ±.5 ±..79.4.5 ±. M /,. ±.4 ±.3.8.3.8 ±.5 [ATLAS-CONF-3-7] ~ Polarisation P b in agreement with extrapolation from and in disagreement at.7 with prediction of % ~ b in agreement with most predictions (-. to -.); measurements in disagreement with.777 Method b Reference Factorization. PRD56 (997) 799 Factorization.8 PRD58 (998) 46 Covariant oscillator quark model.8 Prog. Theor. Phys. (999) 959 Perturbative QCD.7 to.4 PRD65 () 743 Factorization (HQET).777 PLB64 (5) 65 Light front quark model.4 PRD8 (9) 946 HADRON 3 6

b AND c-hadron SPECTROSCOPY HADRON 3 7

EXCITED D J STATES [, JHEP 9 (3) 45] [, JHEP () 5] Ø The quark model predicts many excited states in limited mass regions Ø Ground and P states well established Ø BaBar collaboration has recently found 4 new states decaying to Dπ and/or D*π. Need to be confirmed. [PRD8 ()] Mass (MeV) 3 5 D*(3) D(864) D *(68) D (558) D 3 *(86) 3 D (86) D (8) D *(796) S S D P F D *(479) D (469) D (49) D *(38) D 4 *(384) 4 D 3 (379) 3 D 3 (374) 3 D *(374) [Godfrey&Isgur, PRD3 (985) 89] : Inclusive study of D (à Kππ)π -, D (à Kπ)π and D* π -. Several millions of D s in fb - Ø Natural spin-parity states (J P =, -,,3 - ) can decay to Dπ and D*π Ø Unnatural spin-parity states (J P = -,, -, 3 ) can decay D*π Ø Dπ spectrum: natural spin-parity states cross-feed of all states (expect )à D*π Ø D*π spectrum: all states (expect ). But different angular distribution (ϑ Helicity angle) ü sin ϑ for natural spin-parity ü hcos ϑ for unnatural spin-parity ü Natural/Unnatural component can be enhanced with an ad hoc requirement on ϑ HADRON 3 8

D * Π MASS SPECTRUM 5 5 [, JHEP 9 (3) 45] [, JHEP () 5] pull cos ϑ >.75 enhances unnatural component (residual natural component ~9%) Candidates / (4 MeV) -5 5 4 6 8 3 4 6 8 3 D (4) 3 unnatural states: D J (58), D J (74), D J (3) 5 * - m(d π ) [MeV] Ø cos ϑ <.5 enhances natural component Ø Parameters of the unnatural states are fixed from Step pull Candidates / (4 MeV) -5 5 5 5 4 6 8 3 4 6 8 3 * - m(d π ) [MeV] D * (46) unnatural states more natural states: D J* (65), D J* (76) 3 Ø Parameters of all states fixed from Step & Ø Fit performed in bins of cos ϑ to verify angular distributions dn/d(cosθ H ) 8 6 4 D (4) Unnatural (a) D (4) - -.5.5 cosθ H dn/d(cosθ H ) 5 5 5 D * (4) Natural * (b) D (46) - -.5.5 cosθ H dn/d(cosθ H ) 6 4 8 6 4 D * (65) Natural * (a) D (65) J - -.5.5 cosθ H dn/d(cosθ H ) 4 35 3 5 5 5 D * (76) Natural * (b) D (76) J - -.5.5 cosθ H dn/d(cosθ H ) D J (58) Unnatural 5 5 (a) D (58) J - -.5.5 cosθ H dn/d(cosθ H ) D J (74) Unnatural 3 (b) D (74) J - -.5.5 cosθ H dn/d(cosθ H ) D J (3) Unnatural 5 4 3 (c) D (3) J - -.5.5 cosθ H HADRON 3 9

D Π /D Π - MASS SPECTRA pull Cross-feeds 5 estimated from states appearing in the D*π spectrum pull [, JHEP 9 (3) 45] [, JHEP () 5] 5-5 6-5 6 Candidates / (4 MeV) 6 4 4 5 3 Candidates / (4 MeV) 6 4 4 5 3 4 6 8 3 m(d π ) [MeV] 4 6 8 3 - m(d π ) [MeV] more natural states: D J* (3), D J* (3) Study of D (*) π spectrum from B decays needed to establish spin-parity HADRON 3 Resonance Final state Mass (MeV) Width (MeV) Yields 3 Signif ( ) D (4) D 49.6 ±.±.7 35. ±.4 ±.9. ±.9 ±.7 D(46) D 46.4 ±.4±. 43. ±. ± 3. 8.9 ±. ±.9 DJ (65) D 649. ±3.5± 3.5 4. ±7.± 8.6 5.7 ±. ±.3 4.5 D (76) D 76. ±5.± 6.5 74.4 ± 3.4 ± 37. 4.4 ±.7 ±.7. D J (58) D 579.5 ±3.4± 5.5 77.5 ±7.8± 46. 6.3 ± 3. ± 3.4 8.8 D J (74) D 737. ±3.5±. 73. ±3.4± 5. 7.7 ±. ±. 7. D J (3) D 97.8 ±8.7 88. ±44.8 9.5 ±. 9. D(46) D 46.4 ±.±. 45.6 ±.4 ±. 675. ± 9. ±.3 DJ (76) D 76. ±.± 3.7 74.4 ± 3.4 ±9. 55.8 ±.3 ±. 7.3 DJ (3) D 38. ±4..5 ±.5 7.6 ±.. D(46) D 463. ±.±.6 48.6 ±.3 ±.9 34.6 ±.±. DJ (76) D 77.7 ±.7± 3.8 66.7 ± 6.6 ±.5. ±. ±. 8.8 DJ (3) D 38.(fixed).5 (fixed) 7.6 ±. 6.6

ORBITALLY L= EXCITED B STATES Ø The heavy quark effective theories (HQET) predict the masses of the B (s) mesons by a perturbative expansion of Λ QCD /m b ~ Ø Precise measurements of the excited B and B s meson properties are a sensitive test of the validity of HQET ~s b ~s {u,d,s} ~ L Relative orbital angular momentum ~j = ~ L ~s {u,d,s} Angular momentum of the light quark ~J = ~j ~s b Total angular momentum of the B meson B (s) * B (s) B (s) B (s) * Two Broad States (Γ~ MeV) ~L = ~j =/ ~j =3/ ~J P = Mixing ~s s = ~J P = ~J P = J ~ P = Two Narrow States (Γ~ - MeV) ~s b = j q J P Allowed decay mode B B B / yes no B / no yes B 3/ no yes B 3/ yes yes B K B K Bs / yes no Bs / no yes B s 3/ no yes Bs 3/ yes yes ( à - - Forbidden) HADRON 3

Candidates / ( MeV/c ) Pull STUDY OF B S ** STATES IN THE BK MASS SPECTRUM 8 6 4 - * - B s B K * B s B * - K * B s B - K 5 4 3 5 5 5 3 35 4 6 8 4 6 8 - - m(b K ) - m(b ) - m(k ) [MeV/c ] [, PRL (3) 583 ] [CDF, arxiv:39.596 ] Ø B candidates selected in many decay(j/ψk, D π, D 3π) modes and combined with kaons of opposite charge CDF Ø Confirmation of the B s state Ø Most precise measurements of the B s, B s * and B* masses Ø Observation of the B s *à B * K - decay Ø Measurements of the B s and B s * natural widths Ø Br(B s* à B*K)/Br(B s* à BK) Ø The measured branching ratio and B s * width favour J P = HADRON 3

EVIDENCE OF A NEW EXCITED B STATE IN THE BΠ MASS SPECTRUM ) Events / ( 4 MeV/c 8 6 4 8 3 B N = 55.5 B Q = 39.9 B =.58 A N = 438. A Q = 58.5 A = 8.5 ± 4.4 ±.7 MeV/c ±.99 MeV/c ± 65.4 ±.68 MeV/c ±.99 MeV/c Preliminary - 336 pb s = 7 TeV Data 6 4 4 B π - 3 4 5 3 4 5 m B - m B - m [MeV/c ] m B - m B - m [MeV/c ] B π ) Events / ( 4 MeV/c 4 8 6 3 B N = 3.4 B Q = 39.9 B = 6.8 A N = 44.5 A Q = 6.4 A = 4. [-CONF--53 ] [CDF, arxiv:39.596 ] Ø B /B candidates selected in many decay modes (J/ψK (*), D - /D π, D - /D 3π) and combined with charge pions Ø B and B * are missing in the PDG CDF ± 4.3 ± 3.3 MeV/c ± 4.9 MeV/c ± 74. ±.9 MeV/c ± 4.9 MeV/c CDF Preliminary - 336 pb s = 7 TeV Data - - -3 3 4 5 m B - m B - m [MeV/c ] - - -3 3 4 5 m B - m B - m [MeV/c ] Ø Precise measurements of the B, B * masses and widths Ø Evidence (4.4σ) of a new excited B state: B(597) / HADRON 3 3

SEARCH FOR Ξ CC [, arxiv:3.538 ] Ø All of the ground states with C= or C= have been discovered Ø Three weakly decaying C= states expected: Ξ cc isodoublet and Ω cc isosinglet Ø SELEX reported signals of Ξ cc à Λ c K - π, pd K - : [PRL 89 (), PLB 68 (5) 8] Ø M = 359 ± MeV and τ(ξ cc ) < 3 fs @ 9% C.L. Ø Large production (% of Λ c from Ξ cc ) Ø No confirmation so far Ø looks for Ξ cc à Λ c K - π using.65 fb - Ø The search is performed in wide ranges of mass and lifetime: 33<M<37 MeV <τ<4 fs Ø No signal found ( cc)b( cc! c K ) ( c ) <.4 at the 95% CL Ø The result doesn t confirm or disprove the SELEX signal ) Entries / ( 4 MeV/c 8 6 4 4 5 6 7 8 δm [MeV/c ] HADRON 3 4

OBSERVATION OF NEW b BARYONS Ø : Observation of two new b baryons in the Λbππ mass spectrum, where Λbà Λc(pK-π)π-: Λ*b(59) Λ*b(59) Ø CDF: Confirmation of Λ*b(59) Ø CMS: Observation of a new b baryons in the Ξb-π mass spectrum, where Ξb- à J/ψ(μμ) Ξ-(Λπ): Ξb* (5945) [CMS, PRL 8 () 5 ] [, PRL 9, () 7 ] [CDF, arxiv 3.949 ] 3 5 5 6 4 CMS pp, s = 7 TeV - L = 5.3 fb Opposite-sign data Signalbackground fit Background (b) 8 6 4 5 59 HADRON 3 Ξ* b candidates per MeV Candidates / (.5 MeV/c) They are interpreted as the orbitally (L=) excited Λb states and the JP =3/ Ξb state respectively 59 59 593 594 595 M (Λb π π ) (MeV/ c) 3 4 5 M(J/ψΞ π) - M(J/ψΞ ) - M(π) [MeV] 5

OBSERVATION OF B C à J/ΨK Ø Only few B c decay modes observed before the LHC era: B c à J/ψπ and B c à J/ψμ ν Ø is largely increasing the knowledge about the B c meson. New decays modes have been discovering: B c à J/ψπ π - π and B c à ψ(s) π Ø First observation of the decay B c à J/ψK using fb - [, PRL 8, () 58 ] [CMS, CMS-PAS-BPH--3 ] [, PRL 9, () 3 ] [ATLAS, ATLAS-CONF--8 ] [, JHEP 9 (3) 75] DLL K =lnl(k) lnl( ) 6 4 (a) DLL K < 5 Ø Signal significance 5.σ B(B c! J/ K ) B(B c! J/ ) HADRON 3 =.69 ±.9 ±.5 Ø Agreement with predictions Candidates / ( MeV/c ) Candidates / ( MeV/c ) 8 6 4 Data Total fit B c J/ψ K B c J/ψπ Comb. bkg Part. recon. bkg 6 6 M (J/ψK 64 )[MeV/c 66 ] 3 (c) 5 5 5 6 6 M (J/ψK 64 )[MeV/c 66 ] Candidates / ( MeV/c ) Candidates / ( MeV/c ) 5 4 3 (b) 6 6 M (J/ψK 64 )[MeV/c 66 ] 4 (d) 35 3 5 5 5 5 <DLL K < <DLL K < 5 DLL K > 5 6 6 M (J/ψK 64 )[MeV/c 66 ] 6

B C à J/ΨD S (*) AND B C à J/Ψ K K - Π Ø First observation of B c à J/ψD s (*). The B c à J/ψD s * appears as a cross feed in the J/ψD s mass spectrum Ø Small Q value à Most precise measurement of B c mass m B c = 676.8 ±.44(stat) ±.36(syst) MeV B(B c! J/ D s ) B(B c =.9 ±.57 ±.4! J/ ) B(B c! J/ Ds ) B(B c! J/ D s =.37 ±.56 ±. ) Candidates/(5 MeV/c ) [, PRD 87 (3) ] [, arxiv:39.587 ] 6 5 4 3 Candidates/( MeV/c ) 5 B c! J/ D s 5 5 6. 6.5 6.3 6.35 m(j/ D s ) GeV/c 5.6 5.8 6 6. 6.4 6.6 m(j/ D s ) GeV/c Ø First observation of B c à J/ψK K - π. D s à KKπ and B s à J/ψ KK regions vetoed. Figure : Mass distributions for selected J/ D s pairs. The solid curve represents the result of a fit to the model described in the text. The contribution from the B c! J/ D s decay is shown with thin green dotted and thin yellow dash-dotted lines for the A ±± and A amplitudes respectively. The insert shows a zoom of the B c mass region. 6 4 B(B c! J/ K K ) B(B c! J/ ) =.53 ±. ±.5 6.5 6. 6.5 6.3 6.35 6.4 HADRON 3 7

OBSERVATION OF B C à B S Π Ø Observed B c decays to date are decays where the b quark decays weakly to a c quark but B c à B (s) X decays are foreseen as well Ø Experimental clarification is needed to shed light on the wide range of predictions Ø performed a search based on 3 fb -. The B s meson reconstructed in B s à J/ψϕ and B s à D s - π B c [, arxiv 38.4544 ] c b V cs V ud W u b π d s B s Candidates / ( MeV/c ) 4 3 Data B c B s ( J/ ψφ)π Comb. bkg. B ρ c B s Bc B*π s Candidates / ( MeV/c ) 5 4 3 Data B c B s ( D s Comb. bkg. B ρ c B s Bc B*π s π )π 6 6 64 66 m(b π ) [MeV/c s ] 6 6 64 66 m(b π ) [MeV/c s ] (B c ) (B s) B(B c! B s )=.37 ±.3 (stat) ±. (syst).7.3 ( B c ) 3 HADRON 3 8

) ) ) PRECISE MASS MEASUREMENTS OF THE GROUND STATES [, JHEP 36 (3) 65] [, PRL (3) 8] [, PLB 78 () 4 ] Ø A complete and reliable experimental mass spectrum would allow for precision tests of a variety of QCD models Ø provides precise measurements of masses Ø Momentum scale (known at the level of.3%) remains the largest systematic uncertainty Events / ( 5 MeV/c Events / ( 5 MeV/c Candidates/ ( MeV/c ) 5 5 5 pull 8 6 4 5 5 5 (b) 8 84 86 88 9 9 M(K K K π ) [MeV/c ] 6 4 - -4-6 B J/ψ K 5 55 53 535 * B J/ψ K M(J/ψ K ) [MeV/c ] D D /D s (a) B (b) B Events / ( 5 MeV/c 5 5 5 B s J/ψ φ (e) B s 53 535 54 545 M(J/ψ φ) [MeV/c ] Λ b 5 55 53 535 * M(J/ψ K ) [MeV/c ] Discrepancy (>6σ) between CDF and D about the Ω b mass has been resolved Ω b Ξ b HADRON 3 9

CONCLUSION Ø b and c-hadron production: ü Experimental measurements agree with theoretical predictions in most of the cases ü Theoretical models are able to make predictions at different energies ü Sometimes the experimental precision is much better than theoretical uncertainties Ø b and c-hadron spectroscopy: ü Observation of highly excited D and B states ü Study of the Dπ and D*π mass spectra from B decays could help into identifying the new excited D mesons ü Searches for baryons with two heavy quarks are ongoing with the full data sample HADRON 3 3