The XYZs of cc: 1. Charmonium reminder. 2. The new states: T.Barnes tbarnes@utk.edu ORNL / U.Tenn. Charm2006 Beijing 7 June 2006 The XYZs of cc: 1. Charmonium reminder. 2. The new states: X(3943) Y(3943) Z(3931) Y(4260) cc? cc hybrids!? How to test these possibilities. (My) theor. numbers are from T.Barnes, S.Godfrey and E.S.Swanson, PRD72, 054026 (2005). For BABAR, BELLE, BES, CLEO, GSI, … : All 40 cc states expected to 4.42 GeV, all 139 of their open-charm strong modes and partial widths, all 231 open-charm strong decay amplitudes, all 153 E1 and (some) M1 EM widths.

Charmonium (cc) A nice example of a QQ spectrum. Expt. states are shown with the usual L classification. Above 3.73 GeV: Open charm strong decays (DD, DD* …): broader states except 1D2 2- +, 2- - 3.73 GeV Below 3.73 GeV: Annihilation and EM decays. (rp, KK* , gcc, gg, l+l-..): narrow states.

Minimal quark potential model physics: OGE + linear scalar confinement; Schrödinger eqn (often relativized) for wfns. Spin-dep. forces, O(v2/c2), treated perturbatively. Here… Contact S*S from OGE; Implies S=0 and S=1 c.o.g. degenerate for L > 0. (Not true for vector confinement.)

Fitted and predicted cc spectrum Coulomb (OGE) + linear scalar conft. potential model black = expt, red = theory. Y(4260) JPC = 1- - Z(3931), X(3943), Y(3943) C = (+) states fitted S*S OGE

cc and cc–H from LGT <- 1- + exotic cc-H at 4.4 GeV A LGT cc-sector spectrum e.g.: X.Liao and T.Manke, hep-lat/0210030 (quenched – no decay loops) Broadly consistent with the cc potential model. No LGT cc radiative or strong decay predictions yet. cc and cc–H from LGT <- 1- + exotic cc-H at 4.4 GeV n.b. The flux-tube model of hybrids has a lightest multiplet with 8 JPCs; 3 exotics and 5 nonexotics, roughly degenerate: (0,1,2) +- /-+, 1++,, 1- -. Y(4260)? Small L=2 hfs.

Comparing expt. with theory, especially for 2P cc states, through: The main theme: Comparing expt. with theory, especially for 2P cc states, through: 1st Strong decays 2nd EM (g and gg transitions)

Trivial observations for 2P cc open-charm strong decays: Thresholds DD 3.73 GeV DD* 3.87 GeV (Ds Ds 3.94 GeV - small) J PC-allowed D, D* modes (M < D*D*) c2’ 2++ 23P2 DD, DD* c1’ 1++ 23P1 DD* c0’ 0++ 23P0 DD hc’ 1+ - 21P1 DD* but C = ( -) Looking for both DD and DD* is a good filter! n.b. JP = 1+ DD* final states have both S and D amps. Detailed 2P cc predictions…

Open-charm strong decays: 3P0 decay model (Orsay group, 1970s) qq pair production with vacuum quantum numbers. L I = g y y . A standard for light hadron decays. It works for D/S in b1 -> wp. The relation to QCD is obscure.

One success of strong decay models An historical SLAC puzzle explained: the weakness of y(4040) -> DD e.g. D*D* molecule? After restoring this “p3 phase space factor”, the BFs are: D0D0 : D0D*0 : D*0D*0 0.12 +/- 0.06 0.95 +/- 0.19 [1] +/- 0.31

Y(4040) Y(4040) partial widths [MeV] Y(4040) -> D*D* amplitudes (3P0 decay model): DD = 0.1 DD* = 32.9 D*D* = 33.4 [multiamp. mode] DsDs = 7.8 Y(4040) -> D*D* amplitudes (3P0 decay model): 1P1 = + 0.034 5P1 = - 0.151 = - 2 * 51/2 * 1P1 5F1 = 0 famous nodal suppression of a 33S1 Y(4040) cc -> DD std. cc and D meson SHO wfn. length scale

Expt. preview, M, G and modes, X(3943), Y(3943), Z(3931): J/y

2P cc Strong Widths: 3P0 Decay Model (assuming NR cc potential model masses) DD DD* DsDs 2P 23P2 80 [MeV] 23P1 165 [MeV] 23P0 30 [MeV] 21P1 87 [MeV]

An interesting new charmonium production mechanism! Allows access to C=(+) cc states in e+e- w/o using gg. X(3943) hc’ X(3943) hc c0 No c1 or c2 !? n.b. Eichten: X(3943) may be the 31S0 cc hc’’. [ref] = P.Pakhlov et al. (Belle), hep-ex/0507019, 8 Jul 2005.

Strong Widths: 3P0 Decay Model X(3943) Maybe not 2P? X(3943) = 31S0 hc” ? (Eichten) 33S1 74 [MeV] 31S0 80 [MeV] 3S DD DD* D*D* DsDs 52(10) MeV X(3872) Is the narrow expt width a problem for X(3943) = 31S0 hc” ? Let’s recalculate with M = 3943 MeV and see …

X(3943) Gthy = 70 MeV vs Gexpt = 15(10) MeV Yes the total width is a problem for X(3943) = 31S0 hc”. Gthy = 70 MeV vs Gexpt = 15(10) MeV X(3943) 2 thy. expt.

B -> KY(3943), Y -> w J/y [ref] = S.-K. Choi et al. (Belle), PRL94, 182002 (2005).

Y(3943) Gtot Y(3943) = 23P1 cc? (Too light for cc-H.) theory expt. Expt for Y(3943): B -> KY(3943), Y -> wJ/y G = 87 +/- 22 MeV 1++ cc -> wJ/y is unusual; cc -> virtual DD* e.g. -> wJ/y ? n.b. c1 IS seen in B decays theory expt. Theory for 23P1(3943): G = 135 MeV A strong DD* mode $ ? The only open-charm mode?

Z(3931) gg -> Z(3931) -> DD [ JPC(gg) .ne. 1++ ] [ref] = S.Uehara et al. (Belle), hep-ex/0507033, 8 Jul 2005.

Z(3931) Gtot Z(3931) = 23P2 cc ? (suggested by Belle) Expt for Z(3931): gg -> Z(3931) -> DD G = 20 +/- 8 +/- 3 MeV Ggg * BDD = 0.23 +/- 0.06 +/- 0.04 keV Theory for 23P2(3931): G = 47 MeV DD*/DD = 0.35 Ggg * BDD = 0.47 keV (Ggg from T.Barnes, IXth Intl. Conf. on gg Collisions, La Jolla, 1992.) The crucial test of Z(3931) = 23P2 cc : DD* mode $ ? Gtot thy expt Ggg in http://web.utk.edu/~tbarnes/website/Barnes_twophot.pdf

(How one might make 2P cc states.) EM transitions (How one might make 2P cc states.) What radiative partial widths do we expect from various initial 1- - cc states to 2P cc states?

E1 Radiative Partial Widths 3S -> 2P 33S1 -> 23P2 14 [keV] 33S1 -> 23P1 39 [keV] 33S1 -> 23P0 54 [keV] 31S0 -> 21P1 105 [keV] 3S -> 1P 33S1 -> 3P2 0.7 [keV] 33S1 -> 3P1 0.5 [keV] 33S1 -> 3P0 0.3 [keV] 31S0 -> 1P1 9.1 [keV] blue = known states red = unknown

E1 Radiative Partial Widths 2D -> 2P 23D3 -> 23P2 239 [keV] 23D2 -> 23P2 52 [keV] 23P1 298 [keV] 23D1 -> 23P2 6 [keV] 23P1 168 [keV] 23P0 483 [keV] 21D2 -> 21P1 336 [keV] 2D -> 1F 23D3 -> 3F4 66 [keV] -> 3F3 5 [keV] -> 3F2 14 [keV] 23D2 -> 3F3 44 [keV] 3F2 6 [keV] 23D1 -> 3F2 51 [keV] 21D2 -> 1F3 54 [keV] 2D -> 1P 23D3 -> 3P2 29 [keV] 23D2 -> 3P2 7 [keV] 3P1 26 [keV] 23D1 -> 3P2 1 [keV] 3P1 14 [keV] 3P0 27 [keV] 21D2 -> 1P1 40 [keV]

y(3770) y(3770) -> g ccJ y(3770) -> g cc2 Ref: R.A.Briere et al. (CLEO), hep-ex/0605070 (May 2006). y(3770) -> g ccJ y(3770) -> g cc2 is very sensitive to the 23S1 <-> 3D1 mixing angle q. With q approx -15o, both the e+e- and strong 3770 widths = theor predictions. This q is very interesting: what drives 23S1 <-> 3D1 mixing?

y(3770) Experiment and theory [assuming y(3770) = pure 3D1 cc ]. Ref: R.A.Briere et al. (CLEO), hep-ex/0605070 (May 2006). Experiment and theory [assuming y(3770) = pure 3D1 cc ].

y(3770) Ref: Y.-B.Ding, D.-H.Qin and K.-T.Chao, PRD44, 3562 (1991). new CLEO rad widths: 172 (30) 70 (17) < 21 n.b. ratios of versus J are the most reliable theor predictions. y(3770) -> g ccJ

Y(4260)

e+e- -> Y(4260)ISR, Y -> p+p-J/y [ref] = BaBar, PRL95, 142001 (2005). Not seen in R. Hmmm?! log scale

Y(4260) CLEO: Evidence for Y(4260) in J/y p+ p- and J/y p0p0 channel s [pb] J/y p+ p- 58 +/- 4 J/y p0p0 23 +/- 1 (approx. 2:1 ratio expected for I=0) J/y K+ K- 9 +/- 1 +12 -10 +12 - 8 + 9 - 5 Ref: T.E.Coan et al. (CLEO), PRL96, 162003 (2006); hep-ex/0602034v2.

cc spectrum, potential models (dashed: nonrel L, Godfrey-Isgur R) vs data Possible 1- - state Y(4260). Note no plausible cc assignment exists. A 1- - charmonium hybrid??

cc and cc–H from LGT <- 1- + exotic cc-H at 4.4 GeV A LGT cc-sector spectrum e.g.: X.Liao and T.Manke, hep-lat/0210030 (quenched – no decay loops) Broadly consistent with the cc potential model. No LGT cc radiative or strong decay predictions yet. cc and cc–H from LGT <- 1- + exotic cc-H at 4.4 GeV n.b. The flux-tube model of hybrids has a lightest multiplet with 8 JPCs; 3 exotics and 5 nonexotics, roughly degenerate: (0,1,2) +- /-+, 1++,, 1- -. Y(4260)? Small L=2 hfs.

Characteristics of cc-hybrids. (folklore, mainly abstracted from models, some LGT) States (flux-tube model): The lightest hybrid multiplet should be a roughly degenerate set containing 3 exotic and 5 nonexotic JPC; 0+-, 1-+, 2+-, 0-+, 1+-, 2-+, 1++, 1-- Mass ca. 4.0 – 4.5 GeV, with LGT preferring the higher range. The 1-- should be visible in e+e- but with a suppressed width. (Hybrid models for different reasons predict ycc (r=0) = 0, suppressing Gee .) Decays (flux-tube model and f-t decay model): Dominant open-charm decay modes are of S+P type, not S+S. (e.g. DD1 not DD or DD*). n.b. p1(1600) -> p h’ argues against this model. LGT(UKQCD): Closed-charm modes like cc-H -> cc + light mesons are large! (Shown for bb-H; (bb) is preferentially P-wave, and “light mesons” = scalar pp.)

p-p -> p-h’ p p1(1600) p1(1600) S+S, not S+P ! E.I.Ivanov et al. (E852) PRL86, 3977 (2001). p1(1600) The (only) strong JPC-exotic H candidate signal. p-p -> p-h’ p p1(1600) 1-+ exotic reported in p-h’ S+S, not S+P ! ph’is a nice channel because nn couplings are weak for once (e.g. the a2(1320) noted here). The reported exotic P-wave is dominant!

Strong Widths: 3P0 Decay Model 43S1 78 [MeV] 41S0 61 [MeV] 43(15) [MeV] A warning about hybrid = S+P modes: Theor. decay BFs of the 43S1 cc y(4415). DD DD* D*D* DD0* DD1 DD1’ DD2* D*D0* DsDs DsDs* Ds*Ds* DsDs0*

(As for all states above open-charm thresholds.) Y(4415) A cc state, but the main mode (thy.) is S+P, not S+S ! n.b. PDG says the 4415 decays mainly to “hadrons”. Expt BFs needed! (As for all states above open-charm thresholds.) Y(4415) partial widths [MeV] (3P0 decay model): DD = 0.4 DD* = 2.3 D*D* = 15.8 [multiamp.] DsDs = 1.3 DsDs* = 2.6 Ds*Ds* = 0.7 [m] New S+P mode calculations: DD1 = 30.6 [m] <- MAIN MODE!!! DD1’ = 1.0 [m] DD2* = 23.1 D*D0* = 0.0 Y(4415) - > DD1 amplitudes: (3P0 decay model): 3S1 = 0 <- !!! (HQET) 3D1 = + 0.093

An “industrial application” of the y(4415). Sit “slightly upstream”, at ca. 4435 MeV, and you should have a copious source of D*s0(2317). (Assuming it is largely cs 3P0.)

Summary, conclusions, suggestions, re expt: X(3943), Y(3943), Z(3931) and Y(4260) … 1. X(3943) as 31S0 hc’’, cc ? DD*-only checks, G may be a bit small.. Just measure J P !!! (also for Y and Z!) 2. If Y(3943) is the 23P1 c1’, one expects a large DD* mode, and no DD. 3. gg -> Z(3931) -> DD and DD* if c2’. …

Summary, conclusions, suggestions, re expt: 4. Y(4260) as hybrid? No new cc 1- - expected near this mass: if it exists it’s already something unusual. Theory folklore says hybrids prefer S+P modes, UKQCD says c + light meson(s) may be large. Best approach would be to search for it in all accessible open charm and closed charm modes. e+e- -> DD, DD*, D*D*, DD0*, DD1*; J/y pp, any other (cc) + light meson mode. (Close and Page, hep-ph/0507199v2, PLB628, 215 (2005) gives a detailed list of modes)

The End Summary, conclusions, suggestions, re expt (cont.): X(3943), Y(3943), Z(3931) … 5. E1 radiative transitions from 1- - cc states: You can find all three 23PJ cc states using y(4040) and y(4160) -> gDD, gDD*. e.g. All three E1 rad BFs of the y(4040) are ca. few * 10-4. These could show whether the X,Y,Z (3.9) are 2P cc as speculated. The End