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New Hadron Spectroscopies. Stephen L. Olsen University of Hawai’i. d. u. u. d. s. d. c. d. c. c. c. History:. chadwick. 1930’s: proton & neutron ..all we need??? 1950’s: ,,,,,… “Had I foreseen that, I would have gone into botany” – Fermi

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## New Hadron Spectroscopies

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**New Hadron Spectroscopies**Stephen L. Olsen University of Hawai’i d u u d s d c d c c c**History:**chadwick 1930’s: proton & neutron ..all we need??? 1950’s: ,,,,,… “Had I foreseen that, I would have gone into botany” – Fermi 1960’s: The 8-fold way “3 quarks for Mister Mark” 1970’s add charmed particles 1980’s & beauty 1990’s & (finally?) top Fermi Gell-Mann Richter Ting Lederman Peters Jones**Hadron “zoo”**mesons baryons**Quarks restore economy(& rescue future Fermis from Botany?)**3 quarks (& 3 antiquarks) u+2/3 u-2/3 d-1/3 s-1/3 M. Gell-Mann d+1/3 s+1/3 Baryons: qqq Mesons: q q u+2/3 u+2/3 p: u+2/3 d-1/3 p+: d+1//3 u-2/3 u-2/3 u-2/3 p: p-: d+1/3 u+2/3**Fabulously successful, but…**• quarks are not seen • why only qqq and qq combinations? • What about spin-statistics?**W-**s-1/3 s-1/3 s-1/3 2 of these s-quarks are in the same quantum state Das ist verboten!!**The strong interaction “charge” of each quark comes in 3**different varieties Y. Nambu O. Greenberg W- s-1/3 s-1/3 s-1/3 the 3 s-1/3 quarks in the W- have different color charges & evade Pauli**QCD: Gauge theory for color charges**Nambu Gell-Mann & Fritzsch generalization of QED QED QCD er eb eg scalar charge: e isovector charge: QED gauge Xform QCD gauge Xform + ie A + i ali Gi 1 vector field (photon) 8 vector fields (gluons) eight 3x3 SU(3) matrices**Attractive configurations**eijkeiejek i ≠ j ≠ k dijei ej same as the rules for combing colors to get white: 3 different primary colors color-complementary color eiejek color charges Hence the name: Quantum Chromodynamics**Difference between QED & QCD**QED: photons have no charge QCD: gluons carry color charges gluons interact with each other**Vacuum polarization QED vs QCD**2nf 11CA in QCD: CA=3, & this dominates**QEDQCD difference**Coupling strength a distance**Testing the Standard Model**QCD X Electro-Weak X QED W, Z & t masses Z width sin2qW Asymmetries Cross-sections … decrease in aswith distance Lamb-shift g-2 Atomic spectra …**Tests of QED and EW sectors**Electro-Weak sector (tested @ ~0.01% level) QED (tested @ ppb) Example: (g-2)/2|electron Expt: 1,159,652,188.4(4.3)x10-12 Theory: 1,159,652,201.4(28)x10-12**Test QCD with 3-jet events(& deep inelastic scattering)**as gluon rate for 3-jet events should decrease with Ecm**“running” as**Why are these people smiling?**Probe QCD from other directions**non-qq or non-qqq hadron spectroscopies: Pentaquarks: e.g. an S=+1 baryon (only anti-s quark has S=+1) Glueballs: gluon-gluon color singlet states Multi-quark mesons: qq-gluon hybrid mesons d u u d s d c d c c c**Pentaquarks**“Seen” in many experiments but not seen in just as many others Belle BES BaBar CDF High interest: 1st pentaquark paper has ~500 citations**Experimental situation is messy(many contradictory results)**NA49 pp @ Ecm=17 GeV (fixed tgt) (PRL92, 052301: 237+ citations!) COMPASS mp @ Em =160 GeV (fixed tgt) X(1862): qqssd 1862 ± 2 MeV FWHM = 17 MeV = 5.6 100sof X(1530)s but no hint of X(1862) hep-ex/0503033**Pentaquark Scoreboard**Positive signals Negative results Also: Belle Compass L3 Yes: 17 No: 17**multi-quark mesons?**BK p+p-J/y y’p+p-J/y X(3872) M(ppJ/y)**Seen in 4 experiments**CDF X(3872) D0 X(3872) hep-ex/0406022**Is the X(3872) a cc meson?**Could it be one of these? 3872 MeV These states are already identified**no cc state fits well**hc” hc’ cc1’ y2 hc2 y3 M too low and G too small angular dist’n rules out 1+- 3872 G(gJ/y) way too small G(gcc1) too small;M(p+p-) wrong pp hc should dominate G( gcc2 & DD) too small SLO hep-ex/0407033**back to square 1**Determine JPC quantum numbers of the X(3872)**Use 250 fb-1 ~275M BB prs**X(3872)p+p-J/y y’p+p-J/y Signal (47 ev) Sidebands (114/10 = 11.4 ev)**Areas of investigation**• Search for radiative decays • Angular correlations in XppJ/y decays • Fits to the M(pp) distribution • Search for X(3872)D*0D0**Kinematic variables**BK p+p-J/y Ecm/2 e+ e- B B ϒ(4S) Ecm/2 DE CM energy difference: BK p+p-J/y Beam-constrained mass: Mbc**Select BKg J/y**BKcc1; cc1g J/y X(3872)? M(gJ/y) Mbc Mbc 13.6 ± 4.4 X(3872)gJ/y evts (>5s significance) Bf(XgJ/y) Bf(XppJ/y) =0.14 ± 0.05**Evidence for X(3872)p+p-p0 J/y(reported last summer**hep-ex/0408116) 12.4 ± 4.2 evts B-meson yields vs M(p+p-p0) Br(B3pJ/y) Br(B2pJ/y) Large (near max) Isospin violation!! = 1.0 ± 0.5**Evidence for C=+1is overwhelming**• Bg J/y only allowed for C=+1 • same for B”w”J/y (reported earlier) • M(pp) for Xp+p-J/y looks like a r**Angular Correlations**r Jz=0 J=0 X3872 J=0 K J/y**Strategy: for each JPC, find a distrib 0if we see any**events there, we can rule it out Rosner (PRD 70 094023) Bugg (PRD 71 016006)**0-+**0-+ : sin2q sin2y c2/dof=18/9 q |cosq| c2/dof=34/9 y safe to rule out 0-+ |cosy|**0++**In the limit where X(3872), pp, & J/y rest frames coincide: dG/dcosqlp sin2qlp qlp c2/dof = 41/9 rule out 0++ |cosqlp|**1++**compute angles in X(3872) restframe 1++: sin2ql sin2c c2/dof = 11/9 ql K |cosql| c c2/dof = 5/9 1++ looks okay! |cosc|**Fits to the M(pp)Distribution**J/y XrJ/y in P-wave has a q*3 centrifugal barrier q* X r q***M(pp) can distinguish r-J/y S- & P-waves**P-wave: c2/dof = 71/39 S-wave: c2/dof = 43/39 (CL=0.1%) (CL= 28%) q* roll-off q*3 roll-off Shape of M(pp) distribution near the kinematic limit favors S-wave**Select BD0D0p0 events**D*0D0p0? Preliminary 22±7 signal evts Bf(BKX)Bf(XD*D)=2.2±0.7±0.4x10-4 |DE| |DE|**XDDp rules out 2++**• 1++ : DD* in an S-wave q* • 2++ : DD* (or DDp) in a D-wave q*5 Strong threshold suppression**a 1++ cc state?**• 1++ cc1’ • Mass is off • cc1’ r J/y violates Isospin, should be suppressed. 3872 G(XgJ/y)/G(XppJ/y) Theory: ~ 30 Expt: 0.14 ± 0.05 cc1’ component of the X(3872) is ≤ few %

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