1 / 22

S-Waves & the extraction of b s

S-Waves & the extraction of b s. Sheldon Stone FPCP 2010, Torino, Italy, May 2010. Outline. Mystery of Scalar Mesons Appearances of S-waves D-> K pi  nu Ds-> K+K-pi+ Ds -> K+K-  nu B -> J/psi K* Measuring b s in VV decays J/psi phi phi phi & NP

markku
Download Presentation

S-Waves & the extraction of b s

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. S-Waves & the extraction of bs Sheldon Stone FPCP 2010, Torino, Italy, May 2010

  2. Outline • Mystery of Scalar Mesons • Appearances of S-waves • D-> K pi  nu • Ds-> K+K-pi+ • Ds -> K+K-  nu • B -> J/psi K* • Measuring bs in VV decays • J/psi phi • phi phi & NP • Possible effects of S-waves on bs (Franz example) • A new possibility J/psi f0 decays • Predictions of branching ratios from Ds decays • Theoretical predictions (El-Bennich, Colangelo) • Estimation of possible sensitivity • Conclusions (other places S-waves can appear -> K* mu mu) FPCP 2010, Torino, Italy

  3. Mystery of Scalar Mesons • 0+nonet is not well understood • Compare 0- versus 0+ • For 0- nonet, the mass increases by ~400 MeV for each s quark. Why isn’t this true for the 0+ nonet? • Why aren’t the ao & the s degenerate in mass? • Suggestions that the 0+ are 4-quark states FPCP 2010, Torino, Italy

  4. S-waves in DsK+K-p+ decays • Dalitz analyses (also E687) • Fit using a linear S-wave + Breit-Wigner convoluted with Gaussian for the f. Find 6.3% (8.9%) S-wave for 10 MeV (15 MeV) CLEO Bkgrnd subtracted FPCP 2010, Torino, Italy

  5. S-waves via Interference in semileptonic decays • D+K-+m+: Though K is dominantly K*, FOCUS observed an interfering S-wave amplitude with a rate fraction of (2.7±0.4)% for 0.8 < m(K) < 1.0 GeV • DsK+K-e+: S-wave fraction of for 1.01 < m(K+K-) < 1.3 GeV (BaBar) weighted by cosqV FPCP 2010, Torino, Italy

  6. The S-Wave in BJ/ K* • Two Vectors in final states so a transversity analysis is required • BaBar & Belle measure interference between S & P waves in K* decay angle • The fraction of S-wave intensity is (7.31.8)% for 0.8 < m(Kp) <1.0 GeV • BaBar uses this interference to remove ambiguities in the measurement of cos(2b) B MC no interference BaBar FPCP 2010, Torino, Italy

  7. Measuring bs in Bs Decays • Thus far BsJ/ used exclusively • Bs suggested, for null measurement, as decay phase cancels mixing phase • These modes are Vector- Vector final state, so must disentangle CP+ & CP- final states using an angular analysis Vts Vts FPCP 2010, Torino, Italy

  8. Technique • Without S-waves & DG=0 • A0 P=+ longitudinal, A||P=+ trans, AP= - trans • For Bs replace A by -A. • S-Wave term cannot be ignored (Stone & Zhang [arXiv:0812.2832]) • Must add in S-wave amplitude and finite DG. FPCP 2010, Torino, Italy

  9. All terms [Xieet al, arXiv:098.3627] • Time dependence (for ex.) • Can write FPCP 2010, Torino, Italy

  10. Estimate of S-wave Effect • Adding AS can only increase the experimental error. The size of the effect depends on many factors including the magnitude & phase of the S-wave amplitude, bs, values of the strong phases, detector acceptances, biases.. • One simulation for LHCb by Xieet al • Assumes either 5% or 10% S-wave with phases either 0 or 90o. • Simulates many Pseudo experiments • Bias of -10%, error increases by 15%. Can also use to eliminate ds ambiguity Ignore AS Include AS -2bs -2bs FPCP 2010, Torino, Italy

  11. Estimates of J/y f0(980) • Can use S-wave materializing as fo(980) for CP measurements (Stone & Zhang [arXiv:0812.2832]) • The final state J/yfo is a CP+ eigenstate • No angular analysis is necessary! This is just like measuring J/y Ks. The modes J/yh & J/y h can also be used, but they involved g’s in the decay & thus have lower efficiency at hadron colliders • Define: FPCP 2010, Torino, Italy

  12. Estimate Using Hadronic Ds Decays • M(Bs)-M(J/y)=5366- 3097 = 2270 MeV • M(Ds)-M(p) = 1830 MeV, not too different • Use CLEO result for DsK+K-p+ extrapolated to zero f width to extract B(Dsfp+, fK+K-) = (1.6±0.1)% FPCP 2010, Torino, Italy

  13. Estimate from Dsh+h-p+ • CLEO: B(Dsp+p+p-) = (1.11±0.07±0.04)% • Use BaBarDalitz analysis to estimate fraction of fop+[arXiv:0808.0971] • Estimate (27±2)% of final state is in narrow fo peak There is more S-wave under fo peak fo bkgrnd FPCP 2010, Torino, Italy

  14. Estimate from Ds(f/fo) e+n • Compare semileptonic rates near q2=0 to get maximum phase space CLEO [arXiv:907.3201] foe+n fe+n FPCP 2010, Torino, Italy

  15. Semileptonic estimate • At q2=0, where phase space is closest to BsJ/(/fo) • Note that at q2=0 and in the case of Dsfp, the f is forced into a longitudinal polarization state • CDF measures only 53% fL, so these rates may be too large by x2 FPCP 2010, Torino, Italy

  16. Theory Estimates of Rfo/f • Colangelo, De Fazio & Wang [arXiv:1002.2880] • Use Light Cone Sum Rules at leading order in as. • Prediction 1: B(f) measured = (1.3±2.4)x10-3 • B(fo)=(3.1±2.4)x10-4 (0th order), R=24% • B(fo)=(5.3±3.9)x10-4 (leading order), R=41% • Prediction 2: Using ff for f from Ball & Zwicky[arXiv:hep-ph/0412079]RL =0.13±0.06 (0th order), 0.22±0.10 1st order FPCP 2010, Torino, Italy

  17. Check on Prediction • Note that Colangelo et al predict • BR(Ds foe+) = (2.0+0.5−0.4) × 10−3 , • While CLEO measures • BR(Ds  foe+) = (4.0 ± 0.6 ± 0.6) × 10−3, • Which implies that the calculated form-factor is low by a factor of 2, thus compensating for GfL/Gtotal = 0.53 FPCP 2010, Torino, Italy

  18. QCD Factorization • O. Leitneretal [arXiv:1003.5980] • Assume fBs = 260 MeV, ffo = 380 MeV • Predict B(BsJ/ fo) = 1.70 x 10-4. • B(BsJ/ f) = 9.30 x 10-4. • Rfo/f = 0.187. They show small variation with Bsfo form factor; “annihilation” effects important and decrease fo rate. • “S-wave kaons or pions under the f peak in J/yf are very likely to originate from the similar decay J/yfo. Therefore, the extraction of the mixing phase from J/yf may well be biased by this S-wave effect which should be taken into account in experimental analysis” FPCP 2010, Torino, Italy

  19. Summary of R estimates • Measurement will constrain theories FPCP 2010, Torino, Italy

  20. bs Sensitivity Using J/yfo • From Stone & Zhang [arXiv:0909.5442] for LHCb • Assume Rfo/f = 25% • Assume 2 fb-1 at 14 TeV (~4 fb-1 at 7 TeV) • Error in -2bs • J/y f:0.03 rad (not including S-wave) • J/yfo, fop+p-: 0.05 rad • J/yfo+ J/y h′, h′p+p-g:0.044 rad • The fo mode should be useful FPCP 2010, Torino, Italy

  21. BsJ/fo Signal Selection FPCP 2010, Torino, Italy

  22. Conclusions • S-waves are ubiquitous, they appear whenever looked for, & must be taken into account in BsJ/ f measurements of amplitudes, phases, & CP violation • Suggestions: add S-wave amplitudes in the analysis of BK*m+m- & surely in Bs • BsJ/ fo may be a useful mode to add to the statistical precision on the measurement of -2bs, & hopefully will provide useful checks since angular measurements are not necessary FPCP 2010, Torino, Italy

More Related