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Recent developments in c c , c n and c s spectroscopy:

Recent developments in c c , c n and c s spectroscopy: X(3872), D sJ *(2317) + and D s1 *(2457) + . 1) Basic physics. How well q q worked (charmonium e.g.) 2) The X(3872), D sJ * + (2317) and D s1 * + (2457).

michael-burt
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Recent developments in c c , c n and c s spectroscopy:

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  1. Recent developments in cc , cn and cs spectroscopy: X(3872), DsJ*(2317)+ and Ds1*(2457)+. 1) Basic physics. How well qqworked (charmonium e.g.) 2) The X(3872), DsJ*+(2317) and Ds1*+(2457). 3) What we are reconsidering. (This is a story in progress…) Ted Barnes Physics Div. ORNL Dept. of Phys. and Astro., U.Tenn. HQL2004

  2. basic physics of QCD Small qq separation Large qq separation

  3. LGT simulation showing the QCD flux tube Q Q R = 1.2 [fm] “funnel-shaped” VQQ(R) linear conft. (str. tens. = 16 T) Coul. (OGE) The QCD flux tube (LGT, G.Bali et al; hep-ph/010032)

  4. Charmonium (cc) A nice example of a QQ spectrum. Expt. states (blue) 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.

  5. Fitted and predicted cc spectrum Coulomb (OGE) + linear scalar conft. potential model blue = expt, red = theory. 3D3 (3810) 3D2 (3803) 3D1 (3787) 1D2 (3802) as = 0.5538 b = 0.1422 [GeV2] mc = 1.4834 [GeV] s = 1.0222 [GeV]

  6. What about LGT??? An e.g.: X.Liao and T.Manke, hep-lat/0210030 (quenched – no decay loops) Broadly consistent with the cc potential modelspectrum. No radiative or strong decay predictions yet. cc from LGT <-1- + exotic cc-H at 4.4 GeV Small L=2 hfs. oops… 1+ - cc has been withdrawn.

  7. BelleCollab. K.Abe et al, hep-ex/0308029; S.-K.Choi et al, hep-ex/0309032, PRL91 (2003) 262001. X(3872) from KEK B+ / - -> K+ / -p+p-J/ Y Alas the known y(3770) = 3D1cc. If the X(3872)is 1D cc, an L-excited multiplet is split much more than expected assuming scalar confinement. G < 2.3MeV M = 3872.0 +- 0.6 +- 0.5 MeV Accidental agreement? X = cc (2- + or 2- - or …), or a DD* molecule? M( Do + D*o) = 3871.5 +- 0.5 MeV n.b. M( D+ + D*-) = 3879.5 +- 0.7MeV

  8. CDF II Collab. D.Acosta et al, hep-ex/0312021, PRL to appear X(3872) confirmation (from Fermilab) G.Bauer, QWG presentation, 20 Sept. 2003. n.b. most recent CDF II: M = 3871.3 pm 0.7 pm 0.4 MeV X(3872) also confirmed by D0Collab. at Fermilab. Perhaps also seen by BaBar OK, it’s real… n.b. molecule.ne.multiquark

  9. The trouble with multiquarks: “Fall-Apart Decay” (actually not a decay at all: no HI) Multiquark models found that most channels showed short distance repulsion: E(cluster) > M1 + M2. Thus no bound states. Only 1+2 repulsive scattering. Exceptions: 2) E(cluster) < M1 + M2, bag model: u2d2s2 H-dibaryon, MH - MLL = - 80 MeV. n.b. LLhypernuclei exist, so this H was wrong. 1) nuclei and hypernuclei weak int-R attraction allows “molecules” “VLL(R)” VNN(R) -2mN -2mL 3) Heavy-light R R Q2q2 (Q = b, c?)

  10. X(3872) BelleCollab. K.Abe et al, hep-ex/0308029; S.-K.Choi et al, hep-ex/0309032, PRL91 (2003) 262001. B+ / - -> K+ / -p+p-J /Y y(3770) = 3D1 cc. If the X(3872)is 1D cc, an L-multiplet is split much more than expected assuming scalar conft. G < 2.3MeV Accidental agreement? X = cc 2- + or 2- - or …, or a molecular (DD*) state? M = 3872.0 +- 0.6 +- 0.5 MeV M( Do + D*o) = 3871.5 +- 0.5 MeV n.b. M( D+ + D*-) = 3879.5 +- 0.7MeV Charm in nuclear physics???

  11. cc from the “standard” potential modelS.Godfrey and N.Isgur, PRD32, 189 (1985). A more conventional possibility: X(3872)= cc? 3- -(3D2 is a typo) 2- + 2- - The obvious guess, if cc, is 2- + or 2 - -. No open-flavor strong decays: narrow states.

  12. Charmonium Options for theX(3872) T.Barnes and S.Godfrey, hep-ph/0311169, PRD69 (2004) 054008. (n.b. Eichten, Lane and Quigg have similar results.) Our approach: Assume all conceivable cc assignments for the X(3872): all 8 states in the 1D and 2P cc multiplets. Nominal Godfrey-Isgur masses were 3D3(3849) 23P2(3979) 3D2(3838) 23P1(3953) 3D1(3.82) [y(3770)] 23P0(3916) 1D2(3837) 21P1(3956) We assigned a mass of 3872 MeV to each state and calculated the resulting strong and EM partial widths.

  13. g0 g0 br vector confinement??? controversial Experimental R summary (2003 PDG) How do open-flavor strong decays happen at the QCD (q-g) level? Very interesting open experimental question: Do strong decays use the3P0model decay mechanism orthe Cornell model decay mechanism or … ? e+e-, hence 1-- cc states only. “Cornell” decay model: (1980s cc papers) (cc) <-> (cn)(nc) coupling from qq pair production by linear confining interaction. Absolute norm of G is fixed!

  14. The 3P0 decay model: qq pair production with vacuum quantum numbers. LI = g y y . A standard for light hadron decays. It works for D/S in b1-> wp. The relation to QCD is obscure.

  15. What are the total widths of cc states above 3.73 GeV? (These are dominated by open-flavor decays.) 43(15) MeV 78(20) MeV 52(10) MeV < 2.3 MeV X(3872) 23.6(2.7) MeV PDG values

  16. Strong Widths: 3P0 Decay Model 1D 3D30.6 [MeV] 3D2 - 3D1 43 [MeV] 1D2 - DD Parameters are g = 0.4 (from light meson decays), meson masses and wfns. X(3872) 23.6(2.7) [MeV] (New strong and EM decay results from Barnes, Godfrey and Swanson, in prep.)

  17. Strong Widths: 3P0 Decay Model 3F49.0[MeV] 3F3 87 [MeV] 3F2 165 [MeV] 1F3 64 [MeV] 1F DD DD* D*D* DsDs X(3872)

  18. Strong Widths: 3P0 Decay Model 3S 33S1 74 [MeV] 31S0 67 [MeV] DD DD* D*D* DsDs 52(10) MeV X(3872)

  19. Theor R from the Cornell model. Eichten et al, PRD21, 203 (1980): 4415 4040 4159 D*D* DD* DD Y(4040) partial widths [MeV] (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 = +0.056 5P1 = -0.251 = - 2 * 51/2 *1P1 5F1 = 0 famous nodal suppression of a 33S1Y(4040) cc-> DD std. cc and D meson SHO wfn. length scale

  20. Strong Widths: 3P0 Decay Model 23D3 148 [MeV] 23D2 93 [MeV] 23D1 74 [MeV] 21D2 112 [MeV] 2D DD DD* D*D* DsDs DsDs* 78(20) [MeV]

  21. Theor R from the Cornell model. Eichten et al, PRD21, 203 (1980): 4415 4040 4159 D*D* DD* DD Y(4159) partial widths [MeV] (3P0 decay model): DD = 16.3 DD* = 0.4 D*D* = 35.3 [multiamp. mode] DsDs= 8.0 DsDs*= 14.1 Y(4159) ->D*D* amplitudes: (3P0 decay model): 1P1 = +0.081 5P1 = -0.036 = - 5 -1/2 *1P1 5F1 = -0.141 std. cc SHO wfn. length scale

  22. E1 Radiative Partial Widths 1D -> 1P 3D3 -> 3P2305 [keV] 3D2-> 3P270 [keV] 3P1342 [keV] 3D1->3P2 5 [keV] 3P1134 [keV] 3P0443 [keV] 1D2->1P1376 [keV] X(3872)

  23. Concl:We cannot yet exclude 5 of the 8 1D and 2P cc assignments. However, we do see how to proceed. If X = 1D cc: Total width eliminates only 3D1. Large, ca. 300 – 500 keV E1 radiative partial widths togcJandghc are predicted for 1D assignments ( 3D3, 3D2 ) and 1D2. If Gtot = 1 MeV these are 30% - 50% radiative b.f.s! The pattern of final P-wave cc states you populate identifies the initial cc state. If X = 1D2cc, you are “forced” to discover the hc ! IfX = 2P cc: 23P1 and 21P1 are possible based on total width alone. These assignments predict weaker but perhaps accessible radiative branches to g J/y, gy’ and ghc, ghc’ respectively. NOT to gcJ states. (E1 changes parity.)

  24. DD* molecule options (I prefer this assignment.) This possibility is suggested by the similarity in mass, M(X) = 3872.0 +- 0.6 +- 0.5 MeV M( Do + D*o) = 3871.5 +- 0.5 MeV N.A.Tornqvist, PRL67, 556 (1991); hep-ph/0308277. F.E.Close and P.R.Page, hep-ph/0309253, PLB578, 119 (2004). C.Y.Wong, hep-ph/0311088. E.Braaten and M.Kusunoki, hep-ph/0311147, PRD69, 074005 (2004). E.S.Swanson, hep-ph/0311229. n.b. The suggestion of charm meson molecules dates back to 1976: Y(4040) as a D*D* molecule; (Voloshin and Okun; deRujula, Georgi and Glashow). n.b.2 Could the signal simply be a cusp due to new DD* channels opening? (A.Bacher query.) No one has considered this.

  25. Interesting prediction of molecule decay modes: E.Swanson, hep-ph/0311299: 1+ + DoD*o molecule with additional comps. due to rescattering. J/yro J/y“w” Predicted total width ca. = expt limit (2 MeV). Very characteristic mix of isospins: comparable J/yroandJ/y“w”decay modes expected. Nothing about the X(3872) is input: this all follows from OpE and C.I.

  26. X(3872) summary: The X(3872) is a new state reported by Belle, CDF and DZERO. It is seen in only one mode: J/y p+ p- . It is very narrow, G < 2.3 MeV. The limit ongc1 is comparable to the observed J/y p+ p-. The mass suggests that the X is a deuteronlike DoD*o-molecule. Naïvely, this suggests a narrow total X width of ca. 50 keV and 3:2 bfs to DoDopo and DoDog. However, internal rescatter to (cc)(nn) may be important. This predicts G(X) = 2 MeV and remarkable, comparable “isospin violating” b.f.s to J/yroand J/yw. Possible “wrong-mass” cc assignments to 1D and 2P levels can be tested by their (often large) E1 radiative transitions to g+(cc). The bleedin’ obvious decay mode J/y po poshould be searched for, to test C(X) and establish whether p+ p- = ro.

  27. Where it all started. BABAR: D*sJ(2317)+ in Ds+p0 D.Aubert et al. (BABAR Collab.), PRL90, 242001 (2003). M = 2317 MeV (2 Ds channels), G < 9 MeV (expt. resolution) “Who ordered that !?” - I.I.Rabi (about the m-) Since confirmed by CLEO, Belle and FOCUS. (Theorists expected L=1 cs states, e.g. JP=0+, but with a LARGE width and at a much higher mass.) …

  28. And another! CLEO: D*sJ(2463)+ in Ds*+p0 D.Besson et al. (CLEO Collab.), PRD68, 032002 (2003). M = 2463 MeV, G < 7 MeV (expt. resolution) Since confirmed by BABAR and Belle. M = 2457 MeV. A JP=1+partner of the possibly 0+ D*sJ(2317)+cs ?

  29. (Godfrey and Isgur potential model.) Prev. (narrow) expt. states in gray. DK threshold

  30. Is the same discrepancy evident in the cn sector? Experimental D states (PDG 2002) vs Godfrey-Isgur potential model.

  31. The new broad D states. The 1+ states are not especially low wrt QM. However the status of the 0+ is unclear. (2 expts. differ by 100 MeV.)

  32. Theorists’ responses to the new DsJ* states Approx. 80 theoretical papers have been published since the discovery. There are two general schools of thought: 1) They are cs quark model mesons, albeit at a much lower mass than expected by the usual NRQPMs. [Fermilab] 2) They are “multiquark” states. (“DK molecules”) [UT,Oxon,Weiz.] 3) They are somewhere between 1) and 2). [reality]

  33. M.A.Nowak, M.Rho and I.Zahed, PRD48, 4370 (1993). W.A.Bardeen and C.T.Hill, PRD49, 409 (1994) BEH, PRD68, 054024 (2003).

  34. 2. Multiquark states (DK molecules)[UT,Oxon,Weiz.] T.Barnes, F.E.Close and H.J.Lipkin, hep-ph/0305025, PRD68, 054006 (2003). 3. reality (loop effects now being evaluated) Reminiscent of Weinstein and Isgur’s “KK molecules”.

  35. L’oops

  36. Future: “Unquenching the quark model” Virtual meson decay loop effects, qq <-> M1 M2 mixing. DsJ* states (mixed cs <-> DK …, how large is the mixing?) Are the states close to |cs> or |DK>, or are both basis states important? A perennial question: accuracy of the valence approximation. Also LGT-relevant (they are usually quenched too).

  37. How large are decay loop mixing effects? Charmed meson decays(God91) S.Godfrey and R.Kokoski, PRD43, 1679 (1991). Decays of S- and P-wave D Ds B and Bs flavor mesons. 3P0 “flux tube” decay model. The L=1 0+ and 1+ cs “Ds” mesons are predicted to Have rather large total widths, 140 - 990 MeV. (= broad to unobservably broad).

  38. JP = 0+ (2317 channel) JP = 1+ (2457 channel) The 0+ and 1+ channels are predicted to have very large DK and D*K decay couplings. This supports the picture of strongly mixed |DsJ*+(2317,2457)> = |cs> + |(cn)(ns)> states. Evaluation of mixing in progress. Initial estimates for cc …

  39. L’oops [ J/y - M1M2 - J/y ] 3P0 decay model, std. params. and SHO wfns. M1M2 DM [J/y] PM1M2[J/y] DD- 30. MeV 0.027 DD*- 108. MeV 0.086 D*D*- 173. MeV 0.123 famous 1 : 4 : 7 ratio DD :DD* : D*D* DsDs - 17. MeV 0.012 DsDs*- 60. MeV 0.041 Ds*Ds*- 97. MeV 0.060 1/2 : 2 : 7/2 DsDs : DsDs*:Ds*Ds* Sum =- 485. MeVPcc = 65.% VERY LARGEmass shift and large non-cc component! Can the QM really accommodate such large mass shifts??? Other “cc” states?

  40. L’oops Init.SumDM Pcc [ cc - M1M2 - cc ] 3P0 decay model, std. params. and SHO wfns. J/y - 485. MeV 0.65 hc - 447. MeV 0.71 c2 - 537. MeV 0.43 c1 - 511. MeV 0.46 c0- 471. MeV 0.53 hc -516. MeV 0.46 Aha? The large mass shifts are all similar; the relative shifts are “moderate”. Apparently we CAN expect DsJ-sized (100 MeV) relative mass shifts due to decay loops in extreme cases. cs system to be considered. Beware quenched LGT! Continuum components are large; transitions (e.g. E1 radiative) will have to be recalculated, including transitions within the continuum.

  41. Summary and conclusions: 1) Three new narrow mesons containing at least cc and cs have been reported: X(3872)D*sJ(2317)+D*sJ(2457)+ 2) Theorists expected similar (?) states but at rather different masses. The cs states were expected to have very broad strong decay widths. The interpretation of the new states (qq / two-meson molecules / lin.comb.) is being discussed. Decay loops determine mixing. Radiative transitions should allow definitive tests of qq assignments. There are E1 rate predictions for D*sJ->Ds+ g andDs* + gassuming cs, analogous tothe X(3872) rates we discussed. (e.g. S.Godfrey, hep-ph/0305122, PLB568, 254 (2003).) D*sJ(2457)+->Ds+ greported recently by Belle; strongly favors J=1, as expected. 3) Useful future measurements: A.Precise E1 cc (CLEO; y ’ , y(3770) and c ) and D*sJradiative rates; B.Strong decay model checks (4040, 4159 -> DD, DD*; D*D* PWA) (BES,CLEO). n.b. Y(4415 + d) (at ca. 4440 MeV) a D*sJsource? (expect few % BFs to D*s0(2317) D*sand D*s1(2457) Ds)

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