The meson landscape
Scalars and Glue in Strong QCD
New states beyond
Weird baryons: pentaquark problems
“Diquarks,Tetraquarks, Pentaquarks and no quarks”
1
Theory to Reality via Lattice&Jlab
Strong
Q C D
Only discuss hadrons that are either
Agreed to experimentally exist
Only discuss hadrons that are either
Agreed to experimentally existAgreed experimentally to exist
Only discuss hadrons that are either
Agreed to experimentally existAgreed experimentally to exist
or
Agreed theoretically should exist
Life is hard enough anyway and theorists are easily led astray
ArndtBuccellaCarlsonDyakanovEllisFaberGianniniHuangInoueJaffeKarlinerLipkinMaltmanNussinovOhPolyakovQiangRosnerStechTrillingUVenezianoWilczekXiangYangZhu
If Theta pentaquark doesn’t exist,then these (and many other theorists)should be congratulated on their creativity
Pentaquark
Somethings are deceptively simple
m(Bc) = 6276.5 (4.0) (2.7)
Somethings are deceptively simple
m(Bc) = 6276.5 (4.0) (2.7)
m(c)+m(b) ~ ½[m(psi) + m(upsilon)] = 6278.6
Heavy mass scale of c and b make agreements look artificially good
better than 1 per mille !
Somethings are deceptively simple
m(Bc) = 6276.5 (4.0) (2.7)
m(c)+m(b) ~ ½[m(psi) + m(upsilon)] = 6278.6
Heavy mass scale of c and b make agreements look artificially good
better than 1 per mille !
WHY does it work so well? Constituent d.o.f.robust=gift of nature
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
9460
10023
9860
9893
9913
3686
3097
3415
3510
3556
3772
cc*)
Narrow below MM threshold
Anothergift of nature
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
9460
10023
9860
9893
9913
3686
3097
3415
3510
3556
3772
cc*)
Lattice QCD: Linear: Flux tube…..implies…
Gluonic hybrid mesons
c.m.
e.g. p=1
Exciting the flux tube
Lattice&model agree spectrum; decays in FT; starting in lattice
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
770 780/1020
1460
1700
I=1 vector : I=0 nn*; ss*
1320 1270/1525
1300 1285/1530
1420
+ Problem of nn* ss* flavour mixing
Clean below S-wave MM thresholdsAnd no prominent G expected45
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
770 780/1020
1460
1700
I=1 vector : I=0 nn*; ss*
1320 1270/1525
1300 1285/1530
1420 1370/1500/1710
+ Problem of nn* ss* flavour mixing
44
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
770
1460
1700
I=1 vector : I=0 JP = 2+ 1+ 0+
13201270/1525
13001285/1530
1420 1370/1500/1710980 980/600
43
Far away from qq* lowest multiplets… except for 0++
Glueballs spectrum in YangMills from Lattice
Optimist: is this a signal for scalar glueball?
41
Only scalar glueballbelow 2 GeV
Glueballs spectrum in YangMills from Lattice
Optimist: is this a signal for scalar glueball?
42
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
770
1460
1700
I=1 vector : I=0 JP = 2+ 1+ 0+
13201270/1525
13001285/1530
1420 1370/1500/1710980 980/600
1+
? qq* + GlueballLattice G =1.6 \pm
40
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
770
1460
1700
I=1 vector : I=0 JP = 2+ 1+ 0+
13201270/1525
13001285/1530
1420 1370/1500/1710980 980/600
[qq][q*q*]
39
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
770
1460
1700
I=1 vector : I=0 JP = 2+ 1+ 0+
13201270/1525
13001285/1530
1420 1370/1500/1710980 980/600
Data do not imply GBut given lattice and qq*Does consistent pic emerge?
Can data eliminate it; or even make it robust?
15/38
Scalar Glueball and Mixing
s
n
G
16/37
Scalar Glueball and Mixing
Meson
1710
1500
1370
s
n
G
36
Scalar Glueball and Mixing
Meson G ss* nn*
1710 0.39 0.91 0.15
1500 - 0.65 0.33 - 0.70
1370 0.69 - 0.15 - 0.70
s
n
G
LEAR/WA102Meson pair decays
35
Meson G ss* nn*
1710 0.39 0.91 0.15
1500 - 0.65 0.33 - 0.70
1370 - 0.69 0.15 0.70
s
n
0- 0- meson decays LEAR/WA102
FC Kirk
Scalar Glueball and Mixinga simple example for expt to rule out
Nontrivial correlationwith relative masses heavy
l
lightmiddle
Scalar Glueball and Mixing:how to measure flavour state
Meson G ss* nn*
1710 0.39 0.91 0.15
1500 - 0.65 0.33 - 0.70
1370 0.69 - 0.15 - 0.70
s
n
33
Scalar Glueball and Mixing
Meson G ss* nn*
1710 0.39 0.91 0.15
1500 - 0.65 0.33 - 0.70
1370 0.69 - 0.15 - 0.70
s
n
from BES
A flavour filter for 0++ 0-+ 2++mesons and glueballs
>1 billion 1000 per meson
Challenge: Turn Lattice QCD Glueball spectrum into physics31
flux-tube degrees-of-freedom
c.m.
e.g. p=1
Costs about 1 to 1.5GeV energy to excite phonon“pi/R”Hybrid qq* @ 2GeV; Hybrid cc* @ 4-4.5GeV
Barnes FC Swanson 93
Exotic 1-+ clean example
30
\sim 2.2 GeV ss* quarks LGT \sim 2 GeV ud flavours
Michael…
29
28
Light flavor dangerPi very light = bigger threat e.g. pi b1 below 1-+ hybrid
26/27
Light flavor dangerPi very light = bigger threat e.g. pi b1 below 1-+ hybrid
Heavy flavors: K D B more “normal”KK1 threshold vs ss*hybridDD1 threshold versus cc* hybridBB1 threshold versus bb* hybrid27/26
Predicted 1-+ Hybrid masses (with spin splittings)
25
29/24
“Hybrid” and 3^3S_1almost decoupled
30/23
Predicted 1-+ Hybrid masses (with spin splittings)
Spin hyperfine splittings
1- - (4.25) Y(4260?)1- + (4.1) HQLGT0- + (3.95) X(3940?)
Barnes FC 82Chanowitz Sharpe
e+e- feebly coupled
e+e- \to \psi + X?
22
e+e- \to psi pi pi BaBar sees new vector cc*
Y(4260)
No sign of established3S/2D(4040/4160)4S(4400)in the psi pipi data
Y(4260) thus seemsanomalous
Also no place for extra cc* state
\Gamma(ee) 5-80eVCompare \sim 1 keV !!
But width 90MeV dominantly psi pipi !
Belle e+e- to + X
???
0-+;1-+
33/20
Masses OK. Need to go
Beyond spectroscopy:
Hybrid decays and production.
34/19
What are the general properties of OZI strong decay?
What properties
Michael McNeile 06
FC Burns 06
confirms Flux Tube for hybrid:conventionalLattice S-wave decays now calculated Michael McNeile
Exactly WHAT is Lattice revealing about dynamics:What aspect(s) of Flux Tube model are being confirmed?
2
qq* create in S=1
qq* create in S=0 0
38/15
J – S = “L” Factorisation of S and L
qq* created in S=1
S=0 cannot decay to S=0 + S=0 “spin singlet selection rule”
Factorisation and S=1 creationis powerful result if generally true.
Determine nature of Y(4260) by DD_1 pattern
SL Factorisation and S=1selection rules for psi*(cc*) \to DD_1
Also applies to KK_1 decays of ss* vectorse.g. Jlab around 2.2 GeV
40/13
e+e- KK_1
phi pi pi
Intriguing resonantsignal at 2175 = phi(hybrid)??
2175 – m(phi)=4265 – m(psi)!!??
Jlablook indiffractive
41/12
4260 decay if hybrid
Do data fit with this?
What next (theory and data)
42/11
flux-tube breaking and hybrid decays
c.m.
e.g. p=1
Break tube: S+P states yes; S+S suppressed
Isgur Paton 92 light exotics
FC Page 95 all
43/10
flux-tube breaking and hybrid decays
c.m.
e.g. p=1
Break tube: S+P states yes; S+S suppressed
Isgur Paton 92 light exotics
FC Page 95 all
Look for DD_1 and D*D_0 near threshold Look for psi pipi and h1c eta
44/9
flux-tube breaking and hybrid decays
c.m.
e.g. p=1
Break tube: S+P states yes; S+S suppressed
Isgur Paton 92 light exotics
FC Page 95 all
Look for DD_1 and D*D_0 near threshold Look for psi pipi and h1c eta
Absence of DD; DD*; DsDs …
45/8
Y(4260): D_s and D_s* channels
NoDsDsresonance
eliminatestetraquarkcsc*s*
46/7
Y(4260): D and D* channels
NoDDDD* orD*D*resonance
47/6
The large psi +pi pi = hint of large DD1
D
D_1 uu * pi pi
psi
e+e- psi(hybrid) DD_1
S-wave, relative mom \sim 0; DD_1 interchange constituents to make psi pipi “strongly”
Similar for phi(hybrid) KK_1 phi pipi 48/5
All consistent with predictions for hybrid charmoniumFC+Page 1995
Search DD_1 and D*D_0 in DD\pi\pi
If NOT hybrid cc* then why not/where is it ?!
Can glueballs ever be (dis)proven?
Can glueballs ever be (dis)proven?
Are valence hybrids drowned by continuum mesons?
Can glueballs ever be (dis)proven?
Are valence hybrids drowned by continuum mesons?
Heavy flavours cleaner thy but less interesting for Jlab
ss*g & qq*g at Jlab – flavour dependence and sort out phenom
Lattice challenge = is there 1-+ qq*g signal or is it pi b1 where is the valence hybrid in mass
Can glueballs ever be (dis)proven?
Are valence hybrids drowned by continuum mesons?
Heavy flavours cleaner thy but less interesting for Jlab
ss*g & qq*g at Jlab – flavour dependence and sort out phenom
Lattice challenge = is there 1-+ qq*g signal or is it pi b1 where is the valence hybrid in mass
Lattice challenge = do hybrids really prefer S+P decays(a lot of phenomenology/expt prejudice based on it)
Can glueballs ever be (dis)proven?
Are valence hybrids drowned by continuum mesons?
Heavy flavours cleaner thy but less interesting for Jlab
ss*g & qq*g at Jlab – flavour dependence and sort out phenom
Lattice challenge = is there 1-+ qq*g signal or is it pi b1 where is the valence hybrid in mass
Lattice challenge = do hybrids really prefer S+P decays(a lot of phenomenology/expt prejudice based on it)
General challenge: rate for hybrid photo/electroprod sum rules = not suppressed (hidden assumptions) models primitive
gamma rho
pi
hybrid
N N
yes no
Model assumed this
gamma rho
pi
hybrid
N N
gamma rhohybrid
pi
hybrid
N N
yes
yes
no
no
Model assumed this
Model ignored this
ss*g & qq*g at Jlab – flavour dependence and sort out phenom
Lattice radiative transitions now in progress (heavy flavors)Jlab group……hope for intuition on light flavour rates for Jlab
JLab Hybrids: Theory
JLab Hybrids: Experiment
Diffractive production of 1– at 2175MeV into phi pipi; KK1Hybrid S=0 cant make S=0+S=0: K+K(1P1)=0 test.K1(3P1:1P1) tests for 3S1:3D1:hybrid vector
Scalar Glueball and MixingMeson G ss* nn*
1710 + + +1500 - + - 1370 + - -
s
n
G
3 state mixingRelative phases
2S: 1-
1S: 1-
1D: 1-
2+
1+
0+
3686
3097
3415
3510
3556
3772
cc*)
29801S: 0-
36252S: 0-
Possible 0-+Glueball \sim 3.6 GeVImpact on eta_c’ ??
Compare in B decay, gamma gamma;ee \to psi + eta_c’