Non-standard mesons in BES III? Stephen L. Olsen, Univ of Hawai’i BES annual mtg Shi-dou, May 30-June 2, 2005

non-standard hadrons non-qqq baryons or non-qq mesons: s Pentaquarks: e.g. an S=+1 baryon Glueballs: gluon-gluon color singlet states Multi-quark mesons: qq-gluon hybrid mesons d u u d s u c u c c c

mesons with “hidden charm” are a good place to look u c c c u c standard cc mesons are: best understood theoretically decay properties well known narrow & non overlapping concentrate on charmonium-like particles that don’t match expected properties

What about the y(4.03) ? Conventional wisdom: y(4.03)= y(3S) D*D* DD DD* Ecm(GeV/c)

D momentum spectra @ 4.03GeV DD* DD* D*D* Ling-jun Pan, BES data DD D*D* DD D+ D0 Why is G(y(4.03) D*D*) so huge? DD/DD*/D*D*: 1/20/64 phase-space Charmonium S-wave: 1/4/7 removed D-wave: 1/1/4

Suggestions D* D* y(4.03)=D*D* molecule? a cc-gluon hybrid? c c p,s u PRL 38, 317 p,s D* u u a cc-gluon hybrid? PLB 366, 323 c c

hadronic molecules a new spectroscopy?

DeRujula, Georgi,Glashow, PRL 38, 317 (1977) Many possibilities For BESIII

cc-gluon hybrids another new spectroscopy?

Hybrid states More possibilities For BESIII “normal” cc mesons DD mixes with y(4.03)?? DD cc gluon hybrids More possibilities For BESIII

Belle has candidates for each DD* molecular state: X(3872) S.-K. Choi et al PRL 91, 262001 cc-gluon hybrid: Y(3940) S.-K/ Choi et al, PRL 94, 182882

The X(3872) seen in: C=+ y’ Ispin is violated XgJ/y Xp+p-J/y Xp+p-p0J/y Xp+p-J/y y’ X(3872) M(p+p-p0) MeV M(gJ/y) M(ppJ/y) –M(J/y) Ispin is violated & XD0D0p0 M(D0D0p0) MeV

X(3872) = D0D*0 bound state? JPC = 1++ (favored by DD* models) M ≈ mD0 + mD0* Maximal isospin violation is natural (& was predicted): |I=1; Iz= 0> =1/2(|D+D*->+ |D0D*0>) |I=0; Iz= 0> =1/2(|D+D*-> - |D0D*0>)  |D0D*0> = 1/2(|10> - |00>) G(XgJ/y) < G(XppJ/y) Tornqvist PLB 590, 209 (2004) Equal mixture of I=1 & I =0 Swanson PLB 588, 189 (2004) Swanson PLB 598, 197 (2004)

X(3872) conclusion see hep-ex/0505037 & 0505038 JPC = 1++ cc content is small matches all(?) expectations for a D0D*0 bound state C C c c D* p,s D* u u

BES has a candidate too! from Ling-Jun’s y(4.03)  DX study Study this

Look at DD* region D*+D+p0 D*+D+p0 D*+D+g D*+D+p+ D*0D0p0 D*0D0g

Fits to momentum spectra are poor D* Br’s fixed at PDG values c2/dof = 129/78 CL:0.028% D+ Too few daughters D0 L.J. Pan, PhD thesis

Add some y(4.03)pŨ; ŨDD MŨ~3860 MeV GŨ<12 MeV c2/dof = 100/73 CL: 5% Bry?p=16% ŨDD MŨ~3860 MeV GŨ<12 MeV ŨDD L.J. Pan, PhD thesis

DeRujula, Georgi,Glashow, PRL 38, 317 (1977) Ũ(3860) X(3872)?? ŨDD allowed

Bf(BKY)Bf(YwJ/y)=7.1±1.3±3.1x10-5 cc gluon candidate from Belle: Y(3940) BK wJ/y “Y(3940)” M≈3940 ± 11 MeV G≈ 92 ± 24 MeV Mbc Mbc Mbc Bf(BKY)Bf(YwJ/y)=7.1±1.3±3.1x10-5 S.K. Choi et al, PRL 94, 182882

Y(3940): What is it? Some kind of w-J/y threshold interaction? Brambilla et al (QWG) hep-ph/0412158 Eichten, Lane & Quigg PRD 64, 094019 Barnes, Godfrey & Swanson hep-ph/0505002 Charmonium? Conventional wisdom: wJ/y should not be a discovery mode for a cc state with mass above DD & DD* threshold! Some kind of w-J/y threshold interaction? the J/y is not surrounded by brown muck; can it act like an ordinary hadron? w J/y

Y(3940): What is it (cont’d)? another 4-quark state? M ≈ 2mDs not seen in YhJ/y (h contains ss) width too large?? no p exchange for DSDS s s c ?? PRL 93, 041801 M(h J/y)

Y(3940): What is it (cont’d) ? cc-gluon hybrid? predicted by QCD, decays to DD and DD* are suppressed (“open-charm” thresh = mD + m D** = 4.3 GeV) large hadron+J/y widths are predicted masses expected to be 4.3 ~ 4.4 GeV (higher than what we see) Horn & Mandula PRD 17 898 (1978) Isgur et al PRL 54, 869 (1995) Close PLB 342, 369 McNiele et al PRD 65 094505 c c

“open charm” threshold for hybrids is here DD* D*D* DD Ecm(GeV/c) Hybrid states in this mass range may decay to x J/y (or hc, cc,…) x=light hadrons

Search strategies for BESIII DD(*) molecular states y(4.03)p(g) + Ũ Study DD & DD* masses @ y(4.03) (& y(4.16)??) light cc gluon hybrids y(4.03) g + ccg hybrid Study J/y (cc, hc) + light hadons (g) @ y(4030), y(4160) (& y(4415)??)

Rate estimates (DD(*) molecules) (1yr = 6fb-1) L.-J. Pan’s thesis: ~16% of y(4.03)DDp yield is via: y(4.03)p Ũ(3860) DD If DD recon effic ~0.1% Expect: 103 Ũ(3860)DD/yr including D Br’s

Rate estimates (cc-gluon hybrids) y(4.03) g + (cc gluon hybrid) assume: G(y(4.03)g wJ/y)~G(y(3.77)ppJ/y)~100keV Recon effic wJ/y ~ 1% or gg, or p G(y(4.03)g wJ/y) G(y(3.77)ppJ/y) N(y(4.03)gwJ/y) ~ 103/yr x Can search in many other channels: y(4.03)g (gg,p) + ppJ/y ( hJ/y, ppcc, …)

4.03 (& 4.16 GeV + higher?) may be very interesting. Summary BESIII runs at 4.03 (& 4.16 GeV + higher?) may be very interesting.

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Announcement

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Backup slides

Look at events where 2 D mesons are found ???? Expect ~ 10 ??(3860)DD events L.J. Pan, PhD thesis