Hadron Fragmentation New Results from Belle Matthias Grosse Perdekamp, Illinois Motivation Belle and KEK-B Unpolarized Hadron Fragmentation for Charged Pions and Kaons Global Analysis and Comparison with BaBar Future Measurements of pT Dependence Transversity 2014 Chia, Domus de Maria, Italy June 9th–13th 2014

Motivation: Combined Effort to Measure Transversity Distributions RIKEN BNL Transversity Workshop 2000  Measure CFF and IFF asymmetries in Belle ! D. Boer, A. Ogawa, MGP Belle BaBar e+e- ~ CFF(z1) x CFF(z2) ~ IFF(z1) x IFF(z2) ~ D(z) HERMES COMPASS JLab SIDIS ~ δq(x) x CFF(z) ~ δq(x) x IFF(z) First ideas and attempts at LEP: A. Efremov, et al.(NPPSuppl. 74, 1999) ! RHIC pp  jets ~ G(x1)xδq(x2) x CFF(z) pp  h+ + h- + X ~ G(x1)xδq(x2) x IFF(z) Transversity, δq(x) Tensor Charge Theory Lattice QCD: Tensor Charge = Σq=u,d∫01δq(x)dx June 12th

Available Results on Spin-Dependent and Spin-Independent Fragmentation from Belle Collins FF for charged pions (R. Seidl, Illinois + K. Hasuko RIKEN) Off-Resonance: Phys.Rev.Lett.96:232002,2006 Transversity 2005 On-Resonance: Phys.Rev.D78:032011,2008 Transversity 2008 (Theoretical aspects: Daniel Boer, Nucl.Phys.B806:23-67,2009) Interference FF for pion pairs (A. Vossen Illinois/Indiana + R.Seidl, RIKEN) On-Resonance: Phys.Rev.Lett.107:072004,2011 Transversity 2011 Unpolarized FFs for charged pions and Kaons (M. Leitgab, Illinois) Collins FF for charged Kaons (F.Giordano, Illinois) Unpolarized FF : Phys.Rev.Lett. 111:062002,2013 Kaon Collins FF: released at DIS 2014 Transversity 2014 Also a first at this year’s Transversity workshop: STAR results on IFF (A. Vossen, Indiana) June 12th

Motivation for High Statistics Measurement for Hadron Multiplicities at B-Factories limited data for z>0.7 and at low Q2

KEK-B: High Luminosity, L = 2.1 x 1034cm-2s-1 at low Backgrounds Asymmetric collider: 8 GeV e- + 3.5 GeV e+ Ös = 10.58 GeV , e+e-  ϒ(4S)  BB Ös = 10.52 GeV e+e-  qq (u,d,s,c) Available statistics: 1.8 x 109 events (on resonance) [Collins Analysis] 220 x 106 events (off-resonance) [Spin Averaged D(z)] (Delphi at LEP ~ 6 x 106 events) “on” “off” Belle detector KEKB Critical innovations: Continuous injection 22 mrad beam crossing with crab cavities June 12th

KEK-B Critical Innovations: (A) Continuous Injection (B) 22mrad Beam Crossing with Crab Cavities (A) Constant Beam Current through Continuous Injection (B) Avoidance of parasitic beam crossings without loss of luminosity high energy ring - beam current 22 mrad. crossing crab crossing low energy ring - beam current ∫Ldt vs day time ∫Ldt =1fb-1/day 24 hours June 12th

Belle Detector: Large acceptance, Good Tracking and Particle ID June 12th

Hadron Multiplicity Analysis in Belle   June 12th

Belle Results on Hadron Multiplicities for Charged Pions and Kaons Similar for Kaons June 12th

Comparison with Previous Data Sets Pions Kaons June 12th

Update to DSS Fit Including Belle and BaBar Data from R. Sassot [Fragmentation Function Workshop in December 2013 in Bloomington] Overall normalization factors needed to obtain consistent fit with previous e+e- data sets NBelle=1.058, NBarBar=1.021. At large z, Belle Multiplicities drop off faster than BarBar’s June 12th

Updated Pion Fragmentation Functions from R. Sassot [Fragmentation Function Workshop in December 2013 in Bloomington] Main new feature: gluon FF changes with inclusion of ALICE data Belle and BaBar data consistent with other data sets. Impact limited by uncertainty in the normalization June 12th

Projections for Super Belle KEKB Upgrade & Luminosity Backgrounds & Detectors Projections for di-hadron yields and pT dependent yields

Upgrade Plan for Super KEKB Initial target: 10×higher luminosity ~ 21035/cm2/sec Final goal: L=81035/cm2/sec and ∫L dt = 50 ab-1 Crab cavity 8GeV e- New IR with crab crossing and smaller by* 3.5GeV e+ Assume 5 ab- 1 off-resonance for FF analysis ! New beam-pipe with ante-chamber More RF for higher beam current Damping ring for e+ beam SR

New Detector Required for 20 Times Increased Background (Super -)

Super Belle New particle identifier with precise Cherenkov device: Faster calorimeter with waveform sampling and pure CsI (endcap) New particle identifier with precise Cherenkov device: (i)TOP or fDIRC. KL/m detection with scintillator and next generation photon sensors Background tolerant super small cell tracking detector New dead time free pipelined readout and high speed computing systems Si vertex detector with high background tolerance & fast readout

Observe pT Dependence of Yields for e+e- Annihilation into Hadron Pairs electron Constrain pT-dependence of fragmentation functions h2, z2 pT Combinations: z relative hadron momenta positron

0.2 < z< 0.25 0.5 < z < 0.55 pT[GeV] pT[GeV]   1 10-1 10-2 10-3 10-4 10-5 0.2 < z< 0.25 1 10-1 10-2 10-3 10-4 10-5 0.5 < z < 0.55 Relative Stat. Error Relative Stat. Error pT[GeV] pT[GeV] 1 10-1 10-2 10-3 10-4 10-5 1 10-1 10-2 10-3 10-4 10-5 0.7 < z < 0.75 0.9 < z < 0.95 Relative Stat. Error Relative Stat. Error pT[GeV] pT[GeV] from Martin Leitgab

Summary High statistics hadron multiplicties for charged pions and kaons available from Belle and BaBar. Data sets are consistent with existing data from e+e-, pp and SIDIS after changing the normalization by 5.8% for Belle and 2.1% for BaBar. The difference in normalization is presently not understood and requires further study. Precise measurements of the pT dependence of FF are possible both with Belle I and Belle II data sets in the future. June 12th