Hadron Spectroscopy and Resonances : Review

Home , Hadron, Hadron spectroscopy, Roper resonance

M. Padmanath

Regensburg, Germany

25th July 2018 Lattice 2018

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI @ Hadron spectroscopy and resonances (0/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI @ Hadron spectroscopy and resonances (0/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Introduction @ Hadron spectroscopy and resonances (1/32) Hadron spectroscopy on the lattice

Euclidean two point current-current correlation functions n n Z ∗Z ¯ P i j En(tf ti ) Cji (tf ti ) = 0 Oj (tf )Oi (ti ) 0 = 2E e− − − h | | i n n Correlation matrices out of large basis of hadron interpolating operators (Oj (t)) with desired quantum numbers. X Oj (t) = q(x, t)Γj (x, t)q(x, t) x Quark smearing to improve the overlap with ground states! X q(x, t) = S(x, y)qb(y, t) y

Variational study (GEVP) to extract physical information

n n n Cji (t)vi = λ (t, t0)Cji (t0)vi

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Introduction @ Hadron spectroscopy and resonances (1/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Ground state hadron spectroscopy @ Hadron spectroscopy and resonances (2/32) Light baryons

ETMC PRD90 074501 ’14

PACS-CS PRD87 094512 ’13

QCDSF-UKQCD PRD84 054509 ’11

BMW Science322 1224 ’08

ETMC, Nf = 2 : Alexandrou and Kallidonis, PRD96 034511 ’17

Calculations at physical pion mass (ETMC, Nf = 2) Other measurements with chiral extrapolation to physical pion mass.

ETMC, Nf = 2 + 1 + 1 and BMW results with continuum extrapolation. Recently baryon masses and mass splittings : BMW Science347 1452 ’15; QCDSF-UKQCD 1711.02485; Liu 1612.00103.

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Ground state hadron spectroscopy @ Hadron spectroscopy and resonances (2/32) Heavy baryons

4100

3200 : Expt 017 : HSC 015 : Expt 017 : HSC 015 4000 : ILGTI 013 - 018 : Brown et.al. 014 : ILGTI 013 - 018 : Brown et.al. 014 3000 : TWQCD 017 : PACS-CS 013 : TWQCD 017 : PACS-CS 013 : ETMC 017 : Briceno et.al. 012 3900 : ETMC 017 : Briceno et.al. 012 ) ) : RQCD 015 : Durr et al. 012 : RQCD 015 : Durr et al. 012 V

V 2800 e

e 3800 M M ( (

2600

c 3700 c c M 2400 M 3600

2200 3500 * * * * * c c c c c0 c c c cc cc cc cc 2000 3400 PDGMP et al. (HSC) PRL119 042001 ’17; PRD91 094502 ’15 Alexandrou et al. (ETMC) PRD96 034511 ’17 Brown et al. PRD90 094507 ’14 Brice˜no et al. PRD86 094504 ’12 P´erez-Rubio et al. (RQCD) PRD92 034504 ’15 Namekawa et al. (PACS) PRD87 094512 ’13 ILGTI 1807.00174, 1312.3050 Durr et al. PRD86 114514 ’12 Chen& Chiu (TWQCD) PLB 767 193 ’17

Recently baryon masses and mass splittings : BMW Science347 1452 ’15; QCDSF-UKQCD 1711.02485. Early quenched lattice calculations : Lewis et al. ’01; Mathur et al. ’02; Flynn et al. ’03 Dynamical (light quark) investigations : Liu et al. ’10

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Ground state hadron spectroscopy @ Hadron spectroscopy and resonances (3/32) Recent highlight :Ξ cc

3800

: Expt 017 : HSC 015 3750 : ILGTI 013 - 018 : Brown et.al. 014 : ETMC 017 : PACS-CS 013 : RQCD 015 : Briceno et.al. 012 ) 3700 V e

M 3650 (

c c

3600 M

3550

3500

Aaij et al. (LHCb) PRL119 112001 ’17MP et al. (HSC) PRD91 094502 ’15 Alexandrou et al. (ETMC) PRD96 034511 ’17 Brown et al. PRD90 094507 ’14 Brice˜no et al. PRD86 094504 ’12 P´erez-Rubio et al. (RQCD) PRD92 034504 ’15 Namekawa et al. (PACS) PRD87 094512 ’13 ILGTI 1807.00174, 1312.3050

Ξcc isospin splitting (LQCD), 2.16(11)(17) MeV : BMW Science347 1452 ’15 SELEX measurement (3519 MeV) : Mattson et al. PRL89 112001 ’02 New papers from LHCb on properties ofΞ cc : 1807.01919; 1806.02744 M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Ground state hadron spectroscopy @ Hadron spectroscopy and resonances (4/32) More predictions for heavy hadrons from lattice

4600 12. Postdiction W W * ILGTI 018 Brown et al. 014 cbb cbb PACS-CS 13 Prediction : Mesons 4400 TWQCD 017 0 11. ETMC 017 Briceno et al. 012 Prediction : Baryons RQCD 015 Durr et al. 012 ) HSC 015 10. V 4200 D e

M 9. (

4000 GeV

@ * c

c W Wccb ccb E 8.

E 3800 ¢ * X ¢ X * W W W Xcb cb cb cb cb cb 7. + + B c 0 B c 1 3600 - * - B 0 B c 1 6. c 1/2 + 3/2 + 1/2 3/2 H L H L H L H L Mathur& MP (ILGTI) 1807.00174, 1312.3050 Mathur, MP et al. (ILGTI) 1806.04151 Ωcc : probably the next doubly charm baryon to be observed in LHCb. Precise predictions for charmed-bottom hadrons. Consistent results with other calculations Brown et al. PRD90 094507 ’14 Both calculations treat bottom quarks with NRQCD. In this conference, bottom quarks with relativistic action : Salerno Thu. 09.50 [WDME]; Lytle Fri. 14.20 [HSI]

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Ground state hadron spectroscopy @ Hadron spectroscopy and resonances (5/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Excited hadron spectroscopy @ Hadron spectroscopy and resonances (6/32) Excited charmonium spectrum : An example

Established states in yellow Predicted, undiscovered Neutral XYZ mesons Charged XYZ mesons

Need for a rigorous excited state determination

Open scattering channels?

Olsen, 1511.01589

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Excited hadron spectroscopy @ Hadron spectroscopy and resonances (6/32) Methodology and literature

Large basis of carefully constructed hadron interpolators Mesons : Liao & Manke hep-lat/0210030 ’02; Thomas (HSC) PRD85 014507 ’12 Baryons : Basak et al. (LHPC) PRD72 074501, PRD72 094506 ’05 Morningstar et al. PRD88 014511 ’13. Matrix of correlation functions & Variational study Dudek et al. PRD77 034501 ’08, Michael NPB259 58 (1985) Established and practised by many groups 1 Light mesons : Dudek et al. (HSC) PRL103 262001 ’09, PRD82 034508 ’10 Dudek et al. (HSC) PRD85 014507 ’12 2 Light baryons : Bulava et al. (HSC) PRD82 014507, ’10 Edwards et al. (HSC) PRD84 074508 ’11, PRD87 054506 ’13 3 Heavy mesons : Liu et al. (HSC) JHEP1207 126; Moir et al. JHEP1305 021 Cheung et al. JHEP1612 089; Mohler et al. PRD87 034501 ’13 Bali et al. PRD84 094506 ’11; Wurtz et al. PRD92 054504 ’15 4 Heavy baryons : Meinel, PRD85 114510 ’12 MP et al. (HSC) PRD90 074504 ’14, PRD91 094502 ’15 MP& Mathur (HSC) PRL 119 042001 ’17, 1508.07168. Single hadron approximation. Naive expectation : correct up to (Γ) O M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Excited hadron spectroscopy @ Hadron spectroscopy and resonances (7/32) Excited hadron spectroscopy on lattice : An example

2 1.8 p =0 1.8 p2=0 1.7 1.7

1.6 DsDs 1.6 DD DsDs n 1.5 n DD E E a a 1.5 1.4 1.4 1.3

1.2 1.3

1.1 1.2 A1-+ T1-+ T2-+ E -+ A2-+ A1++ T1++ T2++ E ++ A2++ A1-- T1-- T2-- E -- A2-- A1+- T1+- T2+- E +- A2+-

1.8 1.8 2 p =1 p2=2 1.7 1.7 DsDs

DD DsDs 1.6 1.6 DD n n E 1.5 E 1.5 a a

1.4 1.4

1.3 1.3

1.2 1.2 A1- A2- B1- B2- E2- A1+ A2+ B1+ B2+ E2+ A1- A2- B1- B2- A1+ A2+ B1+ B2+ Charmonium spectrum in diﬀerent inertial frames (L 2 fm) Piemonte Fri. 15.20 [HSI]; Collins, MP, et al. (RQCD) ∼ Spin 0,1,2,3 M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Excited hadron spectroscopy @ Hadron spectroscopy and resonances (8/32) Excited baryon spectroscopy : Example

2.6 Wc D 2.4 2.2 GeV @

c 2. Η

m 1.8 X'c K

0.5 1.6 Xc K - 1.4 m 1.2 1 2+ 3 2+ 5 2+ 7 2+ 1 2- 3 2- 5 2- 7 2-

Edwards, et al. (HSC) PRD84 074508 ’11; MP& Mathur (HSC) PRL 119 042001 ’17 PRD87 054506 ’13 Baryon interpolators : Basak et al. (LHPC) PRD72 074501, PRD72 094506 ’05 Morningstar et al. PRD88 014511 ’13. Light baryons : Bulava et al. PRD82 014507, ’10 Edwards et al. (HSC) PRD84 074508 ’11, PRD87 054506 ’13 Heavy baryons : Meinel, PRD85 114510 ’12 MP et al. (HSC) PRD90 074504 ’14, PRD91 094502 ’15 MP& Mathur (HSC) PRL 119 042001 ’17, 1508.07168.

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Excited hadron spectroscopy @ Hadron spectroscopy and resonances (9/32) 0 LHCb discovery of excitedΩ c baryons

Resonance Energy Width Q.no. 0 + Ωc 2695(2) - 1/2 0 + Ωc (2770) 2766(2) - 3/2 0 Ωc (3000) 3000(1) 4.5(1) ? 0 Ωc (3050) 3050(1) 1(-) ? 0 Ωc (3066) 3066(1) 3.5(-) ? 0 Ωc (3090) 3090(1) 8.7(1) ? 0 Ωc (3119) 3119(1) 1(1) ?

Belle

Aaij et al. (LHCb) PRL118 182001 ’17 Conﬁrmation by Belle : Yelton et al. (Belle) PRD97 051102 ’18

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Excited hadron spectroscopy @ Hadron spectroscopy and resonances (10/32) Experiment vs. lattice predictions

- W Η 3 2 c - 1 2 Energy Expt. Lattice 0.5 X D X'c K S 5 2- ∆E 0 422(1) 464(20) Ωc (3119) - H L ∆E 0 395(1) 409(19) 0.4 3 2 Ωc (3090) D - X K S X'c K 32 c ∆EΩ0(3066) 371(1) 383(21) 1 2- c GeV - H L ∆EΩ0(3050) 355(1) 341(18) @ 0.3 12 c

+ Xc K 0 2 ∆EΩ (3000) 305(1) 304(17) c 1

E ∆E 0 70.7(1) 65(11) 0.2 Ωc (2770) 1 - E 0 − E 1203(2) 1209(7) Ωc 2 ηc E 0.1 3 2+ ————— Spin1 /2,3 /2,5 /2 0. 1 2+ Ωccc : HSC PRD90 074504 ’14 Ξcc andΩ cc : HSC PRD91 094502 ’15 Expt. Lattice ————— Here∆ E = E − EΩ0 . c On anisotropic Nf = 2 + 1 lattices The new states correspond to the excited L ∼ 1.9 fm, at mc = 0.114 p-wave excitations. and mπ = 391 MeV ————— Edwards et al. PRD78 054501 ’08 MP& Mathur (HSC) PRL 119 042001 ’17

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Excited hadron spectroscopy @ Hadron spectroscopy and resonances (11/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Resonances on the lattice @ Hadron spectroscopy and resonances (12/32) Resonances on the lattice& L¨uscher’sprescription

On a ﬁnite volume Euclidean lattice : Discrete energy spectrum Maiani-Testa no-go theorem PLB245 585 (1990) No continuum of states ⇒ No resonances, No scattering Non-interacting two-meson levels are given by q q 2 2 2 2 E(L) = m1 + p~1 + m2 + p~2

2π where p~1,2 = L (nx , ny , nz ). 2π Switching on the interaction makes p~1,2 6= L (nx , ny , nz ). The interactions induce a shift in the momentum, 2π 2 e.g. in 1D p~1,2 = L n + L δ(k). Lüscher’sformula relates Lüscher,NPB354 531 (1991) finite volume level shifts ⇔ infinite volume phase shifts.

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Resonances on the lattice @ Hadron spectroscopy and resonances (12/32) Extensions and other methods Extensions within and beyond elastic scattering : different inertial frames, boundary conditions multiple scattering channels particles with different identities Briceño1411.6944; Hansen 1511.04737 Morningstar et al. https://github.com/cjmorningstar10/TwoHadronsInBox 3-particle scattering : Sharpe Thu. 11.00; Mai Mon. 16.30 [HSI] Briceño,Hansen, Sharpe PRD95 074510, ... Polejaeva and Rusetsky EPJA48 67 ’12 HALQCD method : Iritani Fri. 17.10 [HSI] Determine the potential between scattering particles Extract resonance information solving Schrödingerequation. Ishii et al. PRL99 022001 ’07; PLB712 437 ’12 finite volume Hamiltonian EFT : Constrain free parameters of the Hamiltonian based on lattice spectrum Solve for EVP to extract resonance information. Hall et al. PRD87 094510 ’12 Optical potential : Agadjanov et al. JHEP06 043 ’16 [HSI] Hammer, Pang, Rusetsky, JHEP1709 109 M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Resonances on the lattice @ Hadron spectroscopy and resonances (13/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Meson resonances on the lattice @ Hadron spectroscopy and resonances (14/32) Light mesons : Benchmark investigations

950

et al et al [MeV] et al et al ∗ K 900 Bali Rend`on m Prelovsek Wilson

et al

850 Brett

150 200 250 300 350 400 mπ [MeV] Brett Thu. 08.50 [HSI] Rend`onThu. 09.30 [HSI] Alexandrou et al. PRD96 034525 ’17 Expt :Γ( ρ(770) ππ) 100%;Γ( K ∗(892) Kπ) 100% Multiple lattice investigations→ ∼ (mostly using elastic approximation)→ ∼ Coupled channel study of ππ, KK¯ and πK, ηK systems : Dudek et al. PRL113 182001 ’14; Wilson et al. PRD92 094502 ’15; PRD91 054008 ’15 More results : Hoying, Wed. 15.00; Pittler Thu. 09.10 [HSI]

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Meson resonances on the lattice @ Hadron spectroscopy and resonances (14/32) Light mesons : σ, f0 and f2 resonances

1 1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2

800 1000 1200 1400 800 1000 1200 1400 1600

100 50 100 200 150 300 200 0 Expt.(Isoscalar) : σ/f0(500), f0(980), f2(1270) and f2 (1525) Coupled channel study in ππ, KK¯, ηη, I = 0. σ appears as a stable bound state, whereas f0(980) manifests as a dip in ππ cross section. ⇑ Brice˜no et al. (HSC) PRD97 054513 ’18, PRL118 022002 ’17, PRD88 094505 ’13 Elastic study of σ meson in ππ scattering : Guo et al. PRD98 014507 ’18 Dynamically coupled partial waves in ρπ, I = 2: Woss et al. (HSC) JHEP07 (2018) 043 Include scattering particle with non-zero spin and higher partial wave eﬀects.

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Meson resonances on the lattice @ Hadron spectroscopy and resonances (15/32) Heavy mesons : Ds∗0(2317) and Ds∗1(2460)

+ 0 Ds∗(2317) channel 460 0 1 mπ = 156 MeV Lang et.al. − 4 mπ = 290 MeV 1 mπ = 150 MeV 440

] 2

1 − − 1 420 [fm − δ

[MeV] 400 cot p 2 48 64 64 48 M − 24 32 40 64 64 40 32 24 ∆ 380 + 2 2 2 2 2 2 2 m0 m0− 300 200 100 0 100 200 300 400 + − − − − 360 m1 m1− 2 2 + − p [MeV ] m10 m1− − + m+ m 1 Ds1(2460) channel 340 − − 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 1 mπ = 156 MeV Lang et.al. 2 2 4 mπ = 290 MeV mπ [GeV ] − 1 mπ = 150 MeV

] 2

1 − − * 1 2.5 KD [fm − δ cot p

D 2.4 2 48 64 64 48 − 24 3240 64 64 40 32 24 KD GeV @

3002 2002 10020 1002 2002 3002 4002 E − − − 2.3 p2 [MeV2] ΠΠDs Bali et al. (RQCD) PRD96 074501 ’17 + + 2.2 0 1 ∗ KD and KD elastic scattering on Nf = 2 lattices. Comparison with previous results Lang et al. PRD90 034510 ’14 Masses sensitive to pion mass dependence. 0+ 1+ Decay constants : fV = 114(11) MeV, fA = 194(12) MeV.

Coupled channel Dπ, Dη, Ds K¯ scattering : Moir et al. (HSC) JHEP1610 011 ∗ KD scattering and Ds0(2317): Cheung Thu. 09.50 [HSI] M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Meson resonances on the lattice @ Hadron spectroscopy and resonances (16/32) + Heavy mesons :0 and1 − charmonia

ΩJ Ψ X 3915 DD* Χc0 2P 3.8 Ψ 3770H L DD H L ΠΠΧc0 Ψ 2S H L

D 3.6 H L GeV @ E Χc0 3.4 ΠΠJ Ψ

++ -- 3.2 0 1 J Ψ

Piemonte Fri. 15.20 [HSI]; Bali, MP, et al. (RQCD) Resonance treatment of charmonium excitations : Lang et al. JHEP1509 089 Attempt to investigate0 + and1 − excitations in moving frames.

On CLS ensembles U101 and H105; mπ ∼ 280 MeV and mK ∼ 467 MeV. L(U101) ∼ 2.05 fm and L(H105) ∼ 2.73 fm.

Recent discovery by Belle : E = 3860 MeV compatible with χc0(2P). Chilikin et al. (Belle) PRD95 112003 ’17

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Meson resonances on the lattice @ Hadron spectroscopy and resonances (17/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (18/32) Light baryon spectrum

1.7 LK 1.5 NΗ

D DΠ 1.3 Roper

GeV NΠΠ @ D 1232

E 1.1 NΠ H L 0.9 N D L Naive 0.7 +ve parity -ve parity

Hierarchy contradicting expectations from simple potentials Question : Why such a low lying positive parity nucleon excitation (Roper)! Models motivated by spontaneously broken chiral symmetry Goldstone Boson Exchange models Glozman and Riska, hep-ph/9505422 (1996) Eﬀective ﬁeld theories. Suzuki et al.., PRL104 042302 ’10

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (18/32) Nucleon spectrum on the lattice

3.0

2.5 Experiment QCD (nucleon) )

V QCD (Roper) e QCD (overlap + SEB) G 2.0 ( QCD (clover + SEB) N QCD (clover + variation large) M QCD (clover + variation small) 1.5 QCD (overlap + variation) BGR Cyprus (twist mass) Cyprus (clover) 1.0 CSSM JLab

0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 m2 (GeV2) Liu Thu. 12.00 [HSI] Γ(N(1440) Nπ) 65%, with a width of 350 MeV. → ∼ ∼ All lattice calculations using purely qqq structures. First excited lattice level consistently &1700 MeV (Roper), except χQCD. χQCD uses a chiral overlap action, unlike other calculations. A diﬀerent analysis procedure : Sequential Empirical Bayesian (SEB)!

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (19/32) Nucleon spectrum on the lattice

this paper CSSM BGR 3.0

2.5

2.0

1.5

1.0 0 0.05 0.1 0.15 0.2 0.25

Edwards, et al. (HSC) PRD84 074508 ’11; PRD87 054506 ’13 Extensive variational study of light baryon excited states by HSC. Using carefully constructed large basis of interpolators. Basak et al. (LHPC) PRD72 074501, PRD72 094506 ’05 First excitation of nucleon on lattice found & 1700 MeV.

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (20/32) Nucleon spectrum on the lattice

Isovector Scalar Correlator 0.000

0.001 Need of chiral fermion action like in χQCD studies!

0.002 Use of Sequential Empirical Bayesian (SEB)! m u 0.003 m

i ⇐ Liu Thu. 12.00; Fallica Thu. 12.20 [HSI] n i M

0.004 e t a t S

0.005 t The eﬃciency of operators to scan nodal structures! s o h G

0.006 π

η Roberts et al. PLB06 056 ’13; PRD89 074501 ’14 0.007 Liu et al. 1403.6847 0.008 Overlap 0.12 fm Wilson/2.4 0.12 fm 0.009 220 240 260 280 300 320 340 Pion Mass (GeV) Form factors of the nucleon excitations Kamleh et al. 1711.05413 Form factors of hadron resonances ⇓ Leskovec Wed. 15.20; Baroni Thu. 10.10 [HSI]

Old calculations with local qqqqq¯ structures. Spectrum lacking any levels untill ∼ 1.9 GeV. ⇐ Leinweber 1511.09146, 1608.03051

All this said, a simple concern remains! No resonance treatment yet!

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (21/32) Looking for Roper resonance on the lattice

Aim to determine the excited lattice spectrum of nucleon (P=+) and perform a phase shift analysis.

Challenges : exponential degradation of SNR, large no. of Wick contractions, annihilation diagrams, huge computational and storage costs, non-zero spin and complicated phase shift analysis. Silvi Fri. 16.30; Paul Fri. 16.50 [HSI]; Lang& Verduci PRD 87 054502 ’13

First attempt, we limit ourselves to zero momentum frame.

Include interpolators with qqq as well as all baryon-meson scattering channels relevant up to 1.65 GeV on the lattice [PACS-CS, m 156MeV, m L 2] ∼ π ∼ π ∼ qqq-type interpolators, Nπ in p-wave and Nσ in s-wave. e.g. Nπ P 1 1 1 1 1 π 1 N P O = CG( 2 , 2 1ml , 2 ms )CG( 2 , 2 1Iz , 2 Iz ) Ylml (Rk)π(Rk)Nms ( Rk) π N | | R O − Iz ,Iz ,ms ,ml ∈ h Work with an assumption : N(1440) from elastic Nπ scattering!

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (22/32) Pion-Nucleon (p-wave, I = 1/2) elastic scattering Non-interacting system of Nπ and Nππ scattering channels.

1.6

1.5 Nπ (int.) m (exp) 1.4 Roper

1.3 N(1)π(−1) N(0)π(0)π(0)

E [GeV] 1.2

1.1

1 N(0) 0.9 2.5 3 3.5 4 4.5 L [fm]

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (23/32) Pion-Nucleon (p-wave, I = 1/2) elastic scattering Nπ coupled with a Roper like resonance. Lang, MP et al. PRD95 014510, ’17 Lattice Elastic N-π

1.6 2 2 1.5 Nπ (int.) m (exp) 1.4 Roper 1.8 1.8

1.3 N(1)π(−1) 1.6 1.6 N(0)π(0)π(0) N(1)π(−1) E [GeV] 1.2

E [GeV] 1.4 1.4 1.1 N(0)π(0)π(0) 1 1.2 1.2 N(0) 0.9 1 1 N(0) 2.5 3 3.5 4 4.5 L [fm] Low lying Roper resonance does not arise on the lattice within elastic Nπ scattering. Coupling between scattering channels?[ Nπ, Nππ(∆π, Nσ)] Nσ Nσ Study of spectral overlaps! |hΩ|O |n = 2(Nππ)i| . |hΩ|O |n = 3(Nπ)i| Comparisons with HEFT predictions! Other possible reasons for the absence of resonance related level a) Fermions with chiral symmetry! Liu Thu. 12.00; Fallica Thu. 12.20 [HSI] b) 3-particle scattering study! Mai Mon. 16.30; Sharpe Thu. 11.00 [HSI] c) ... ?

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (23/32) Pion-Nucleon (p-wave, I = 3/2) elastic scattering

Γ(∆(1232) Nπ) 100% → ∼ 0 ΓBW 117 MeV 1 3 2 ∼ δ BW ,exp cot

3 g 16.9 −2 ∆Nπ π

cm ∼ m q P2 = 0, H P2 = 1, G g 2 ————————— P2 = 3, F P2 = 3, F 1 2 P2 = 4, G 2 Andersen et al. PRD97 014506 ’17 −4 Darvish Thu. 08.30 [HSI] 1 1.5 2 Ecm-mN mπ ∆(1232) as a resonance using lattice QCD. Nπ elastic scattering in p-wave and isospin 3/2.

Nf = 2 + 1 dynamical gauge ensembles [CLS]; m 280 MeV, mK 460 MeV, L 3.7 fm. π ∼ ∼ ∼ BW m∆ = 1344 MeV and g∆Nπ = 19.0(4.7) More results in this conference : Silvi Fri. 16.30; Paul Fri. 16.50 [HSI]

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Light baryon resonances @ Hadron spectroscopy and resonances (24/32) Outline

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (25/32) Beyond baryons and mesons in experiments

Olsen, 1511.01589

X(3872) Pc (4450) & Pc (4380) Belle PRL91 262001, LHCb PRL115 072001

Z(4430)+ X (3915) LHCb PRL112 222002, Belle PRL94 182002 (was Y(3940)) M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (25/32) XYZ studies on the lattice

Lattice studies in search of X(3872) candidate assume DD¯∗ elastic scattering. Prelovsek and Leskovec PRL111 192001 ’13 Lee et al. 1411.1389 Admixture of¯cc and DD¯∗. Pure molecule unlikely. No signiﬁcant tetraquark Fock component! MP et al. PRD92 034501 ’15 + No explanation for Zc (3900) as well. Prelovsek et al. PRD91 014504 ’15 Many systematics unaddressed. All are exploratory studies. Extensive and systematic investigation by HSC. Looking for candidates with tetraquark signatures. In isospin 0 and isospin 1 channel of charmonium-like spectrum. No conclusive evidence. ⇐ Cheung et al. JHEP1711 033 Cheung et al. JHEP1711 033

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (26/32) Doubly heavy tetraquarks : possibly stable system

Heavy Quark Symmetry implies for a suﬃciently heavy “heavy” quark, the doubly heavy tetraquarks should be stable to strong decays. Carlson et al. PRD37 744 (1988); Eichten and Quigg PRL119 202002 ’17 For a heavy-light meson-like system of doubly charm baryons

M(Ξ∗ ) − M(Ξ ) 3 QQ QQ → M(VQ ) − M(PSQ ) 4 Brambilla et al PRD72 034021 ’05

Data : Brown et al PRD90 094507 ’14

Figure : Lewis CHARM-2018

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (27/32) b¯bud¯ and b¯bls¯ tetraquarks on lattice Francis et al. PRL118 142001 ’17

Study of pseudovector doubly bottom tetraquarks on Nf = 2 + 1 PACS-CS lattices Correlation matrices out of tetraquark as well as meson-meson interpolators

Binding energies :∆ Eb¯bud¯ = 189(10) MeV and∆ Eb¯bus¯ = 98(7) MeV Studies based on LQCD potentials for static quarks in presence of light hadrons P + +43 indicating bound state in I (J ) = 0(1 ).∆ EB.E. = 90 36 MeV Bicudo et al. PRD96 054510 ’17 − − M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (28/32) More on doubly heavy tetraquarks

60 −

120

(MeV) − E ∆

180 − ud¯b¯b I(J P ) = 0(1+) us¯b¯b uc¯b¯b 240 − 0.15 0.30 0.45 0.60 2 2 mπ (GeV) Junnarkar, MP et al. (ILGTI) 1712.08400 Extensive study of quark mass dependence on binding energies of doubly heavy tetraquarks. On Nf = 2 + 1 + 1 HISQ ensembles (MILC) Bottom quark treated non-relativistically. Light to charm quark masses using overlap action. Correlation matrices out of tetraquark as well as meson-meson interpolators Binding energies from diﬀerence in the lowest non-interacting levels M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (29/32) Pentaquark (QQqqq¯ ) systems

δt t δt

Alberti et al. PRD95 074501 ’17 Static quark potential in the presence of light hadrons.∆ E ∼ [−5, −1] MeV robust to FSE. Recent news in this conference ⇓

1.6 3 3 3 3 6-1 6-2 N(2)J/ψ(-2) 1.5 )[ GeV ] c η − + 1.4 3 5 Pc(4449) Pc (4380)( )& Pc (4450)( ) + m 2 2 1 1 3 3 2 2 Pc(4380)N(1)J/ψ(-1) J / ψ 1.3 Λb → J/ψpK : LHCb PRL115 072001 ’15

( 3 m 1.2

1 4 1 1

- N(0)J/ψ(0) Early calculations with signiﬁcantly large n 1.1 E - + - + - + light quark masses. G1 G1 G2 G2 H H

Beane et al. (NPLQCD) PRD91 114503 ’15 N − J/ψ interaction at mπ =266 MeV. No signature for pentaquarks. Skerbis Fri. 15.40 ⇑ Sugiura Fri. 18.10 [HSI] M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (30/32) Beyond hadron spectroscopy : Baryon-baryon interactions

80 HAL QCD 150 Point sources A1 NPLQCD Distillation N1 60 125 Finite-volume analysis This work, distillation This work, FV-analysis 100 40

[MeV] E1 [MeV]

E 75 E

∆ ∆ 20 E5 50 0 25

0 -20 400 500 600 700 800 900 1000 0 200 400 600 800 1000 1200 m [MeV] m [MeV] π Francisπ et al. 1805.03966

Nf = 2 study of H-dibaryon at SU(3) symmetric point at m 960 MeV. π ∼ L¨uschertype analysis on data from multiple inertial frames . Binding energy,∆ E = 19 10 MeV at m 960 MeV. ± π ∼ This conference : results from Nf = 2 and Nf = 2 + 1 Hanlon Thu. 12.40 [HSI] Other baryon-baryon interaction studies Iritani Fri. 17.10; Doi, Fri. 17.50 [HSI]@ mπ(phys) [HALQCD] Berkowitz Tue. 11.15 [Plenary] M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (31/32) Summary

1 Introduction

2 Ground state hadron spectroscopy

3 Excited hadron spectroscopy

4 Resonances on the lattice

5 Meson resonances on the lattice

6 Light baryon resonances

7 Beyond baryons and mesons

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (32/32) Summary

Precision measurements of ground states are now well established and lattice QCD is quite successful in postdicting/predicting ground state hadrons

Ground state as well as excited state baryons are being investigated by various groups. Confronting all the challenges, investigating multiple and adequately large volumes are necessary to understand these resonances!

Diﬀerent groups are practising resonance treatment to study various hadrons. Very promising direction.

Coupled channel treatment : Need of the hour. Some cases even call for studies involving 3-particle scattering. Theory is in development. Mai Mon. 16.30; Sharpe Thu. 11.00 [HSI]

Beyond baryons and mesons : Promising platforms to study. Predictions can motivate experiments to search for such states. Still a lot of exercises to do!

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (32/32) Thank you ...

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (32/32) Acknowledgements

Thanks to the Lattice 2018 organizers for the kind invitation.

Thanks to my collaborators : G. S. Bali, S. Collins, R. G. Edwards, P. Junnarkar, C. B. Lang, L. Leskovec, N. Mathur, D. Mohler, S. Mondal, M. Peardon, S. Piemonte, S. Prelovsek, A. Sch¨aferand S. Weish¨aepl.

Thanks to people who sent/gave me inputs : R. Brice˜no,J. Bulava, S. Cali’, J. Dudek, G. Endrodi, K.F. Liu, A. T. Lytle, A. Palasseri, S. Paul, G. Rend`on, U. Skerbis, F. Stokes, A. Veerappan and H. Wittig.

Acknowledge support from EU funding under grant No. MSCA-IF-EF-ST-744659.

Thanks to S. Gottlieb for help with LatticeNews.

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (32/32) Others I did not cover! Apologies

Review on scattering processes from lattice QCD. Brice˜no,Dudek and Young, Rev.Mod.Phys. 90 025001 ’18

Charm quenching eﬀects on spectral quantities Cali’ Fri. 14.00 [HSI]

Hadrons in magnetic ﬁelds. Bali et al. PRD97 034505 ’18; 1805.10971

Other topics that I have missed to discuss or not discussed to satisfactory level.

M. Padmanath (UR) @ Lattice 2018, East Lansing, MI Beyond baryons and mesons @ Hadron spectroscopy and resonances (32/32)