CHARMED BOTTOM BARYON SPECTROSCOPY. Zachary S. Brown, William Detmold, Stefan Meinel, Konstantinos Orginos

Transcription

1 CHARMED BOTTOM BARYON SPECTROSCOPY Zachary S. Brown, William Detmold, Stefan Meinel, Konstantinos Orginos 1

2 OUTLINE Landscape of heavy baryon spectroscopy Details of our calculation Extrapolations Results 2

3 LANDSCAPE Significant experimental progress in recent years Many singly heavy baryon observations Productive period for LQCD spectroscopy of heavy baryons Group N f S H a 1 t (GeV) L (fm) Bowler et al. 0 tree clover Lewis et al. 0 D , 2.2, Mathur et al. 0 NRQCD 1.8, , 2.1 Flynn et al. 0 NP clover Chiu et al. 0 ODWF Na et al Fermilab 2.2, 1.6, Liu et al RHQ Briceño et al RHQ 1.6, 2.2, Alexandrou et al. 2 Osterwalder-Seiler 3.5, 2.8, Namekawa et al RHQ from H.W. Lin [1] (extended to present) Ω b, Ξ cc CONTROVERSY 3

4 LANDSCAPE Splitting(Stat)(Extrap)(Scale) from H.W. Lin [1] (not current) Experiment B s B d 71.2(2.2)(1.2)(4.2) 87.1(0.6) Λ b B d 340(11)(8.1)(24) 341.0(1.6) Ξ b B d 484.7(7.7)(6.2)(32) 513(3) Σ b B d 615(15)(12)(40) 554(3) Ξ b B d 672(10)(9.1)(44) Ω b B d 749.2(9.8)(9.0)(49) 786(7)/886(16) Λ b B s 261(10)(8.5)(19) 253.9(1.7) Ξ b Λ b 157.2(5.2)(3.4)(9.0) 172(3) Σ b Λ b 274(13)(13)(17) 213(3) Ξ b Λ b 335(15)(10)(20) Ω b Λ b 414(12)(9.5)(25) 445(7)/545(16) Ξ b Σ b 62.6(2.6)(2.0)(3.9) Ω b Ξ b 81.5(2.7)(3.4)(4.9) Test agreement between lattice/expt. and lattice/lattice 4

5 LANDSCAPE GeV Liu et al. direct Liu et al. splitting Na et al. a0.12 fm Flynn et al. Mathur et al. Chiu et al. from PDG [2] c c c c c cc cc Test agreement between lattice/expt. and lattice/lattice 5

6 LANDSCAPE LQCD QM RTQM RQM FHT HQET M cc MeV LQCD 1 N c HQET RQM FHT M b MeV from H.W. Lin [2] and Refs. therein Test agreement between lattice/models 6

7 GOAL OF OUR CALCULATION: 16 Comprehensive calculation of the low lying heavy baryon spectrum Include all states with charmed and bottom quarks. Mass (GeV)

8 GOAL OF OUR CALCULATION: 16 Comprehensive calculation of the low lying heavy baryon spectrum Include all states with charmed and bottom quarks. Include mixed charmed bottom baryons Mass (GeV)

9 DETAILS OF THE CALCULATION Use ensembles generated by RBC/UKQCD collaboration [3] Iwasaki gauge action a , fm 2+1 flavors of dynamical DWF with Mass ranges: m vv π m vv L 2.7fm = ( ) MeV, m ss π K = ( ) MeV L 5 = 16 = ( ) MeV Relativistic heavy quark action [4] for charmed quarks Non-perturbatively tune ν and m 0 Use tree level values for c E and c B NRQCD for bottom accurate through order v 4 One loop improved c 4 calculated by Tom Hammant [5] 9

10 INTERPOLATING OPERATORS AND FITTING METHODOLOGY: BARYON OPS Use baryon operators of the form: O 5 [q, q,q ] α = abc (Cγ 5 ) βγ q a β q b γ (P + q ) c α, O j [q, q,q ] α = abc (Cγ j ) βγ q a β q b γ (P + q ) c α, Use different smearing to construct operator basis: Simultaneous matrix fits, optimized ranges: 2 x 4 for {qqq, qqq} 2 x 2 for {QQQ} aeeff aeeff aeeff aeeff O[c, c, b] O[c, c, b] O[ c, c, b] O[c, c, b] O[c, c, b] O[ c, c, b] O[ c, c, b] O[ c, c, b] χ 2 /d.o.f. =1.4 t/a 10 χ 2 /d.o.f. =0.94 aeeff aeeff aeeff aeeff t/a O[c, c, b] O[c, c, b] O[ c, c, b] O[c, c, b] O[c, c, b] O[ c, c, b] O[ c, c, b] O[ c, c, b]

11 CHIRAL / CONTINUUM EXTRAPOLATIONS M B = M 0 (µ)+ B (µ)+m (B) 1 (µ)+m (B) 3/2 (µ) +O a 2 Tiburzi [6] for singly heavy (coupled fits, SU(2), extended to O (1/m Q ) ): M Λ M Σ M Σ = M Σ,Λ Σ,Λ + f 2 8 λ 3 2 λ 1 λ 1 m 2 π vv + f 2 4 λ 4 λ 2 λ 2 m 2 π ss + g 2 3 M (3/2) g 3,Λ M (3/2) g 3,Σ M (3/2) g 3,Σ + g M (3/2) g 2,Σ M (3/2) g 2,Σ Mathur et. al [7] for doubly heavy (coupled fits, SU(2)): MΞ M Ξ = M 0 + (1/2) (1/4) H f 2 σ 2 m2 π vv f 2 σ m 2 π ss + g 2 1 M (3/2) Ξ QQ M (3/2) Ξ QQ. Assume chiral dependence to be negligible for triply heavy: M Ω ( ) QQQ = M 0 + c a a 2 11 FV corrections from Detmold et al. [8], g widths from Detmold et al. [9]

12 CHIRAL / CONTINUUM EXTRAPOLATIONS Λ c 2.2 Ξ c Σ c Ξ c Σ c 2.4 Ξ c m 2 π (GeV 2 ) m 2 π (GeV 2 ) 12

13 CHIRAL / CONTINUUM EXTRAPOLATIONS Ξ b Λ b Ξ b Σ b Ξ b Σ b m 2 π (GeV 2 ) m 2 π (GeV 2 ) 13

14 CHIRAL / CONTINUUM EXTRAPOLATIONS: RESULTS Baryon Lattice (GeV) Expt. (GeV) Baryon Lattice (GeV) Expt. (GeV) Λ c 2.137(74) Λ b 5.456(114) Σ c 2.444(81) Σ b 5.781(96) Σ c 2.518(82) Σ b 5.802(97) Ξ c 2.372(58) Ξ b 5.760(80) Ξ c 2.526(62) Ξ b 5.947(81) - Ξ c 2.600(62) Ξ b 5.971(81) - Ω c 2.615(67) Ω b 6.008(80) Ω c 2.690(67) Ω b 6.036(80) - 14

15 CHIRAL / CONTINUUM EXTRAPOLATIONS: RESULTS Baryon Lattice (GeV) Baryon Lattice (GeV) Baryon Lattice (GeV) Ξ cc 3.558(39) Ξ cb 6.877(52) Ξ bb (53) Ξ cc 3.627(54) Ξ cb 6.915(62) Ξ bb (56) Ω cc 3.689(38) Ω cb 6.973(48) Ω bb (51) Ω cc 3.773(38) Ω cb 7.040(48) Ω bb (51) Ω ccc 4.794(9) Ω ccb 7.989(11) Ω ccb 8.012(12) Ω cbb (9) Ω cbb (11) Ω bbb (10) 15

16 CONSIDERATION OF UNCERTAINTIES All statistical uncertainties Systematics may enter through several sources: Optimization routine for extracting masses Absence of NNLO correction terms to chiral extrapolations M = M 0 + O m 4 π vv + O m 4 πvs + O m 2 πvv m 2 π vs Currently being explored... but how do our results compare? 16

17 RESULTS: CHARM COMPARISONS GeV c c c c c Briceno et al. Namekawa et al. Alexandrou et al. Liu et al. Na et al. Brown et al. c c c GeV Briceno et al. Namekawa et al. Alexandrou et al. Liu et al. Na et al. Brown et al. cc cc cc cc ccc 17

18 RESULTS: BOTTOM COMPARISONS Lewis et al. Brown et al. Lin et al. Na et al. Detmold et al Lewis et al. Brown et al. Na et al. GeV 5.7 GeV b b b b b b b b 10 bb bb bb bb 18

19 RESULTS: MIXED COMPARISONS GeV Roberts et al. (QM) Martynenko et al. (RTQM) Ebert et al. (RQM) Roncaglia et al. (FH) Mathur et al. (lattice) Brown et al. (lattice) GeV Roberts et al. (QM) Martynenko et al. (RTQM) Brown et al. (lattice) cb cb cb cb 4 ccc ccb ccb cbb cbb bbb 19

20 FUTURE OUTLOOK Still need to nail down systematic uncertainties Possible repetition of calculation with larger operator basis and relativistic bottom quarks? THANK YOU 20

21 References: [1] J. Beringer et al. (Particle Data Group), Phys. Rev. D86, (2012) [2] H. W. Lin, Chin. J. Phys. 49 (2011) 827 [arxiv: [hep-lat]] [3] Y. Aoki et al., Continuum Limit Physics from 2+1 Flavor Domain Wall QCD, Phys.Rev., vol. D83, p , [4] A. X. El-Khadra, A. S. Kronfeld, and P. B. Mackenzie, Phys. Rev. D55, 3933 (1997), hep-lat/ [5] T. C. Hammant, A. G. Hart, G. M. von Hippel, R. R. Horgan and C. J. Monahan, Phys. Rev. Lett. 107, (2011) [arxiv: [hep-lat]] [6]B. C. Tiburzi, Baryon masses in partially quenched heavy hadron chiral perturbation theory, Phys.Rev., vol. D71, p , [7]T. Mehen and B. C. Tiburzi, Doubly heavy baryons and quark-diquark symmetry in quenched and partially quenched chiral perturbation theory, Phys.Rev., vol. D74, p , [8] W. Detmold, C.-J. D. Lin, and S. Meinel, Axial couplings in heavy hadron chiral perturbation theory at the next-toleading order, Phys.Rev., vol. D84, p , [9] W. Detmold, C.-J. D. Lin, and S. Meinel, Axial couplings and strong decay widths of heavy hadrons, Phys.Rev.Lett., vol. 108, p , 2012.