xyz states - thomas jefferson national accelerator … an effective field theory with ! (i) chiral...
Post on 03-May-2018
219 Views
Preview:
TRANSCRIPT
Cassidy, D.B.; Mills, A.P. (Jr.) (2007). "The production of molecular positronium". Nature 449 (7159): 195–197
Multi-electron States
1946: Wheeler suggests that Ps2 might be boundWheeler, J. A. Polyelectrons. Ann. NY Acad. Sci. 48, 219–238 (1946).
1946: Ore proves it is unbound
1947: Hylleraas & Ore prove it is boundHylleraas, E. A. & Ore, A. Binding energy of the positronium molecule. Phys. Rev.71, 493–496 (1947).
2007: Ps2 is observed
��J/� ��hc
�DD̄� �D�D̄�
���(nS)��hb(nP )
�K��
Zc(3900) Zc(4025) Zc(4200)
Zc(4475)
Z1(4050)Z2(4250)
Zb(10610)Zb(10650)
K��cJ K�J/�
�BB̄�
Multi-quark States
pJ/�
Pc(4380)Pc(4450)
Adiabatics K.J. Juge, J. Kuti and C.J. Morningstar, ``Ab initio study of hybrid anti-b g b mesons,'' Phys. Rev. Lett. {82}, 4400 (1999)
QQ̄
V1(mq,mq̄, r) = −br − CF12r
α2s
π
!CF − CA
!ln
"(mqmq̄)1/2r
#+ γE
$$
V2(mq,mq̄, r) = −1rCF αs
%1 +
αs
π
%b0
2[ln (µr) + γE ] +
512
b0 −23CA +
12
!CF − CA
!ln
"(mqmq̄)1/2r
#+ γE
$$&&
V3(mq,mq̄, r) =3r3
CF αs
%1 +
αs
π
%b0
2[ln (µr) + γE − 4
3] +
512
b0 −23CA+
+12
'CA + 2CF − 2CA
'ln
"(mqmq̄)1/2r
#+ γE − 4
3
((&&
V4(mq,mq̄, r) =32αsσ3e−σ2r2
3√
π
V5(mq,mq̄, r) =1
4r3CF CA
α2s
πln
mq̄
mq(1)
Loop Corrections
QQ̄
Instantons
U. Loring, B.C. Metsch and H.R. Petry, ``The Light baryon spectrum in a relativistic quark model with instanton induced quark forces: The Strange baryon spectrum,'' Eur. Phys. J. A {10}, 447 (2001) [hep-ph/0103290].
QQ̄
Pion Exchange
L.Y. Glozman and D.O. Riska, ``The Spectrum of the nucleons and the strange hyperons and chiral dynamics,'' Phys. Rept. {268} (1996) 263
QQ̄
Spin-Dependence
N. Brambilla, A. Pineda, J. Soto, and A. Vairo, The QCD potential at O(1/m), Phys. Rev. D63 (2001) 014023, [hep-ph/0002250].
QQ̄
Y. Koma and M. Koma, ``Scaling study of the relativistic corrections to the static potential,'' PoS LAT {2009}, 122 (2009) [arXiv:0911.3204 [hep-lat]].
QQ̄
QQ̄g
A large collection of pre-LGT ideas: !
(i) flux tube excitation !(ii)constituent vector particle !(iii) string excitation !(iv)bag mode
N. Isgur and J. Paton, Phys. Rev. D31, 2910 (1985).
R. Giles and S. H. Tye, Phys. Rev. Lett. 37, 1175 (1976)
D. Horn and J. Mandula, Phys. Rev. D17, 898 (1978)
T. Barnes, Nucl. Phys. B158, 171 (1979); P. Hasenfratz, R.R. Horgan, J. Kuti and J.M. Richard, Phys. Lett. 95B, 299 (1980); F. de Viron and J. Weyers, Nucl. Phys. B185, 391 (1981); M.S. Chanowitz and S.R. Sharpe, Phys. Lett. B132, 413 (1983).
R.L. Jaffe and K. Johnson, Phys. Lett. 60B, 201 (1976)
J.J. Dudek, ``The lightest hybrid meson supermultiplet in QCD,'' Phys. Rev. D {84}, 074023 (2011)
QQ̄g
Lattice points to a quasi-gluonic excitation with and an excitation scale of order 1 GeV
JPC = 1+�
QQQ
H. Ichie, V. Bornyakov, T. Streuer and G. Schierholz, “The flux distribution of the three quark system in SU(3)”, arXiv:hep-lat/0212024.
C. Alexandrou, P. De Forcrand and A. Tsapalis, Phys. Rev. D 65, 054503 (2002).
T. T. Takahashi, H. Suganuma, Y. Nemoto and H. Matsufuru, Phys. Rev. D 65, 114509 (2002).
N. Cardoso and P. Bicudo, `Color fields of the static pentaquark system computed in SU(3) lattice QCD,'' Phys. Rev. D {87}, no. 3, 034504 (2013)
QQQ̄Q̄QQQQQ̄
S. Furui, A.M. Green and B. Masud, ``An analysis of four quark energies in SU(2) lattice Monte Carlo using the flux tube symmetry,'' Nucl. Phys. A {582}, 682 (1995)
L =g√2fπ
!d4xψ̄(x)γµγ5τ
aψ(x)∂µπa(x)
o�e
N.A. Tornqvist, ``From the deuteron to deusons, an analysis of deuteron-like meson meson bound states,'' Z. Phys. C {61}, 525 (1994)
F. Close, C. Downum, Phys. Rev. Lett. 102, 242003 (2009), 0905.2687 F. Close, C. Downum, C.E. Thomas, Phys. Rev. D81, 074033 (2010), 1001.2553
o�e
D� � [D�]P
D1 � [D�]S
There are channels with S-wave interactions!
E.E. Kolomeitsev and M.F.M. Lutz, ``On Heavy light meson resonances and chiral symmetry,'' Phys. Lett. B {582}, 39 (2004)
J. Nieves and E. Ruiz Arriola, ``Properties of the rho and sigma Mesons from Unitary Chiral Dynamics,'' Phys. Rev. D {80}, 045023 (2009)
u�PT
L. Roca, J. Nieves and E. Oset, ``The LHCb pentaquark as a $\bar{D}^*\Sigma_c-\bar{D}^*\Sigma_c^*$ molecular state,'' arXiv:1507.04249 [hep-ph].
more mesons
F.K. Guo, C. Hanhart, G. Li, U.G. Meissner and Q. Zhao, ``Effect of charmed meson loops on charmonium transitions,'' Phys. Rev. D {83}, 034013 (2011)
D. Diakonov, V. Petrov and M. Polyakov, Z. Phys. A 359, 305 (1997). !T.D. Cohen,``Chiral soliton models, large N(c) consistency and the theta + exotic baryon,'' Phys. Lett. B {581}, 175 (2004)
SU(3) chiral soliton model treated with collective quantization.
But, the theta has excitations that are finite in the large Nc limit, and hence are inconsistent with the DPP assumptions.
The standard analysis of SU(3) solitons is only justified in the large Nc limit which plays an essential role in two ways:
(i) It justifies the use of the classical static hedgehog configurations
(ii) effects of quantum fluctuations around the hedgehogs are suppressed by 1/Nc.
DPP argued that the anti-decuplet should not be dismissed as a large Nc artifact.
chiral solitons
M.A. Nowak, M. Rho and I. Zahed, ``Chiral doubling of heavy light hadrons: BABAR 2317-MeV/c**2 and CLEO 2463-MeV/c**2 discoveries,'' Acta Phys. Polon.B { 35}, 2377 (2004) !M.A. Nowak, M. Rho and I. Zahed, Phys. Rev.D48 (1993) 4370 (hep-ph/9209272). !Bardeen and C. T. Hill, Phys. Rev.D49(1994) 409 (hep-ph/9304265).
�0�1�
��
�0+
1+
�
m(D1)�m(D�) = m(D0)�m(D)
chiral doublers
O. Lakhina and E.S. Swanson, ``A Canonical Ds(2317)?,''Phys. Lett. B {650}, 159 (2007) [hep-ph/0608011].
Construct an effective field theory with (i) chiral symmetry (ii)heavy quark symmetry
S. Dubynskiy and M.B. Voloshin, ``Hadro-Charmonium,'' Phys. Lett. B {666}, 344 (2008)
(multipole expansion)
hadrocharmonium
M.E. Peskin, Nucl. Phys. B 156 (1979) 365;
O. Lakhina and E.S. Swanson, ``Hybrid meson potentials and the gluonic van der Waals force,'' Phys. Lett. B {582}, 172 (2004)
hadrocharmonium
|{qq}3̄c(A)3̄f (A)0+(A)⇤ |{qq}3̄c(A)6f (S)1+(S)⇤
‘good’ ‘bad’
repulsive
3� 3 = 3̄ + 6
(qqq) = [qq]3̄q � Q̄q
(qq̄qq̄) = [qq][q̄q̄]� QQ̄
(qqqqq̄) = [qq][qq]q̄ � QQq̄
diquarksR.L. Jaffe, hep-ph/0409065
M. Ida and R. Kobayashi, Prog. Theor. Phys. 36, 846 (1966)
D.B. Lichtenberg and L.J. Tassie, PR155, 1601 (1967)
A. Selem and F. Wilczek, hep-ph/0602128
R.L. Jaffe, PRD15, 267 (1977)
|0++⇥ = |[cq]S [c̄q̄]S ;J = 0⇥ (1)
|0++⇥⇥ = |[cq]V [c̄q̄]V ;J = 0⇥ (2)
|1++⇥ =1⌅2
(|[cq]S [c̄q̄]V ;J = 1⇥+ |[cq]V [c̄q̄]S ;J = 1⇥) (3)
|1+�⇥ =1⌅2
(|[cq]S [c̄q̄]V ;J = 1⇥ � |[cq]V [c̄q̄]S ;J = 1⇥) (4)
|1+�⇥⇥ = |[cq]V [c̄q̄]V ;J = 1⇥ (5)|2++⇥ = |[cq]V [c̄q̄]V ;J = 2⇥ (6)
Maiani, Riquer, Piccinini, Polosa; PRD72, 031502 (2005)
Maiani, Polosa, Riquer; PRL99, 182003 (2007)
Bigi, Maiani, Piccinini,Polosa, Riquer; PRD72, 114016 (2005)
Maiani, Polosa, Riquer; arXiv:0708.3997
Maiani, Piccinini,Polosa, Riquer; PRD71, 014028 (2005)
Assume a spin-spin interaction
Diquarks and the New Charmonia
M([cq]V ) = 1933M([cq]S) = 1933
diquarks
R.F. Lebed, ``A New Dynamical Picture for the Production and Decay of the XYZ Mesons,'' arXiv:1508.03320 [hep-ph]. !S.J. Brodsky and R.F. Lebed, Phys. Rev. D 91, 114025 (2015) [arXiv:1505.00803 [hep-ph]].
Hadronization occurs at large r, which enhances the coupling to 𝜓(2S) over J/𝜓, in agreement with experiment.
P+c = [c̄(ud)]3 [cu]3̄
diquarks
Similarly,
The diquarks separate to large distance, suppressing the “fall apart” decay mode.
Attempt a “microscopic” cusp model.
Y (4260)� �DD̄� Y (4260)� ��J/�
gDD� · exp(��(s�Y )/�2�Y ) exp(��(sDD�)/�2
DD�)
[separable nonrelativistic model; solve exactly]
cusps
[iterate all bubbles]
D. V. Bugg, Europhys. Lett. 96, 11002 (2011)
D. V. Bugg, Int. J. Mod. Phys. A 24, 394 (2009)
0
10
20
30
40
50
60
70
4 4.02 4.04 4.06 4.08 4.1 4.12 4.14
even
ts
m(DD*) (GeV)
0
10
20
30
40
50
60
70
80
90
4 4.02 4.04 4.06 4.08 4.1 4.12 4.14
even
ts
m(DD*) (GeV)
no evidence for π D* dynamics, background, or bubble
�D�D� = 0.3 GeV
attractive bubble
repulsive bubble
�D�D� = 0.2 GeV
�D�D� = 0.4 GeV�D�D� = 0.3 GeV
cusps
**
E.S. Swanson,``Cusps and Exotic Charmonia,’' arXiv:1504.07952 [hep-ph].
Z.Y. Zhou and Z. Xiao, ``Distinguishing cusp effects and near-threshold-pole effects,’' arXiv:1505.05761 [hep-ph].
F.K. Guo, C. Hanhart, Q. Wang and Q. Zhao, `Could the near-threshold XYZ states be simply kinematic effects?,'' Phys. Rev. D {91}, no. 5, 051504 (2015)
cusps
Conclusions
• many XYZs; not all of them are resonances! • cusp effects can be important and should be accounted
for when modelling • theory evolutionary landscape is largely unconstrained
(we rely on experiment and, increasingly, lattice for help)
top related