Preliminary Update on the HVP Determination

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1 Preliminary Update on the HVP Determination M. Davier, A. Hoecker, B. Malaecu, Z. Zhang Overview Reult Summary Zhiqing Zhang (LAL, Oray) 1 /17

2 Overview a Had µ [ x ] GR 1969 BEG 1972 BLO 1975 CNPR 1976 KNO 1985 B 1985 CLY 1985 J 1986 LPV 1987 BJPV 1989 MD 1990 J 1991 DDS 1995 EJ 1995 BP 1995 MZ 1995 BW 1996 S 1996 ADH 1998 DH 1998a DH 1998b GKSN 1998 KS 1998 BP 2001 TY 2002 DEHZ 2003a HMNT 2003 DEHZ 2003b HMNT 2004 GJ 2004 BP 2005 TY 2005 HMNT 2007 D 2009 DHMZ 2011 HLMNT 2011 JS 2011 J 2011 BP 2011 BDSS 2012 e e baed e e τ baed α (5) had(m 2 Z) [ x 2 ] LO Hadronic Vacuum Polarization (HVP) being the mot uncertain part for a µ & Δα ha been the focu over lat 5 decade. The preciion i teadily improving thank to more precie/complete e e annihilation (& tau) data tate of the art technique for data interpolation, combination and error correlation treatment Davier, Hoecker, Malaecu, Zhang, for Standard Theory Eay in the 60 th Anniverary of CERN, publihed recently by World Scientific Zhiqing Zhang (LAL, Oray) 2 /17

3 Overview Project at Oray initiated by Alemany, Davier, Hoecker in 1998 joined by Zhang ince 2003 and Malaecu ince 2009 with contribution from a few other, e.g. Eidelman, Yuan Relative (%) δa had, LO μ Δα (5) had 1998 [ADH] 2.1 [e e ] 2.2 [e e ] 1.3 [e e tau] 2.2 [e e tau] 2003 [DEHZ] 1.0 [e e ] 0.8 [tau] 2009 [DHMZ] [e e ] 0.64 [tau] 2011 [DHMZ] 0.61 [e e ] 0.36 [e e ] 0.67 [tau] 0.40 [tau] 2017 [DHMZ] 0.49 [e e ] 0.34 [e e ] Uncertainty on a µ reduced by 20% wrt 2011, and a factor of >4 over 20 year Tau le precie now and involve iopin breaking correction Zhiqing Zhang (LAL, Oray) 3 /17

4 Combination Procedure (HVPTool) The integration of data point belonging to different experiment, with different withinexperiment and interexperiment correlated ytematic error, and with different data denitie require a careful treatment DHMZ approach (HVPTool ince 2009): Quadratic interpolation of the data point/bin for each experiment Local weighted average between interpolation performed in infiniteimal bin (1 MeV) Full covariance matrice: correlation between data point of an experiment (ytematic error), between experiment and channel (VP, luminoity, ) Conitent error propagation uing peudo experiment (toy) Poible bia teted in 2π channel uing a GS model: negligible for quadratic interpolation, but not for linear model (trapezoidal rule) Zhiqing Zhang (LAL, Oray) 4 /17

5 Main New Input for the Update 39 excluive channel (v. 22 for 2011) Previou evaluation ued etimation from iopin ymmetry for quite a few unmeaured channel, ~(0.69 ± 0.07)% of a µ had, LO π π : KLOE2012, BES2015 π π 2π 0 : Babar2016 2π 2π : Babar2012, CMD32017 K S K L : Babar2014, CMD32016 K K : SND2016 K S K ± π, K K π 0, K S K L π 0 : Babar2011 K K ππ, K K 2π 0 : Babar2011 K S K L 2π, 2K S 2π: Babar2014 K S K L 2π 0, K S K ± π π 0 : Babar K2π: Babar2012 (update), CMD K2π 0 : Babar2012 (update) 2K L 2π: etimated by CP ymmetry many other (mall cro ection) channel Zhiqing Zhang (LAL, Oray) 5 /17

6 The Dominant 2π Channel Cro ection [nb] 3 2 ρ(770) ρ ω mixing TOF OLYA CMD CMD2 06 CMD2 03 KLOE08 KLOE KLOE12 BES SND DM1 DM2 BABAR ρ(1450) ρ(1700) 1 ρ(2300)? 1 e e π π Zhiqing Zhang (LAL, Oray) 6 /17

7 Cloer Comparion of Different Meaurement Cro ection(exp) / Combination e e π π δ(yt error): 0.5% BABAR Cro ection(exp) / Combination e e π π % KLOE08 KLOE KLOE12 Cro ection(exp) / Combination BES Cro ection(exp) / Combination e e π π 0.9% CMD2 06 CMD Zhiqing Zhang (LAL, Oray) 7 /17 e e π π % SND

8 Relative Weight & Inconitency Dominated by Babar except [~0.85, 0.97] GeV where KLOE ha larger weight Relative weight in combination e e π π BABAR KLOE08 KLOE KLOE12 BES SND CMD2 03 CMD2 06 Other exp Error cale factor e e π π Inconitency between meaurement reflected by large cale factor defined by q 2 local /n dof a la PDG approach (~15% increae on δa µ had ) Zhiqing Zhang (LAL, Oray) 8 /17

9 Four Pion Channel Error reduction: a factor of 1.7 (2017 v 2011) Dicrepancy with le precie tau data Cro ection [nb] e e 2π 2π CMD DM1 DM2 OLYA e e CMD2 SND CMD3 BABAR combined τ ALEPH 5 Cro ection [nb] e e π π 2π 0 OLYA SND BABAR e e combined τ ALEPH Babar: 3.1% below 2.7GeV (wa ~% with prel reult) Overall: Error reduction: a factor 2.3 (2017 v. 2011) Zhiqing Zhang (LAL, Oray) 9 /17

10 KKbar Channel Error reduction: a factor of 1.6 (2017 v 2011) Cro ection [nb] e e K S K L DM1 OLYA CMD2 CMD3 SND BABAR 1 2 Cro ection [nb] e e K K OLYA CMD DM1 DM2 SND CMD2 BABAR Concern: Babar ha δ(yt)~0.7% but σ(φ KK) > CMD2 (SND) by 5.1% (9.6%) Preliminary CMD3 data how dicrepancie the other way around ~5% (Babar), ~11% (CMD2) Zhiqing Zhang (LAL, Oray) /17

11 KKbarπ Channel (Very Recent Babar Reult) Zhiqing Zhang (LAL, Oray) 11 /17

12 Improvement of 2017 Update over 2011 Verion Excluive data integrated up to 1.8 GeV and in charm region [3.7 5] GeV pqcd otherwie Channel a had μ [ ] 2017 a had μ [ ] 2011 δa had, LO μ reduction π π ± 1.13 ± 2.20 ± ± 1.22 ± 2.50 ± % 2π 2π ± 0.03 ± 0.27 ± ± 0. ± 0.43 ± % π π 2π ± 0.06 ± 0.48 ± ± 0.14 ± 1.17 ± % K K ± 0.24 ± 0.28 ± ± 0.27 ± 0.58 ± % K S K L ± 0.06 ± 0.18 ± ± 0.18 ± 0.25 ± % KK bar π 2.45 ± 0.06 ± 0.12 ± 0.07 Et:2.39 ± 0.07 ± 0.12 ± % KK bar 2π 0.85 ± 0.02 ± 0.05 ± 0.01 Et:1.35 ± 0.09 ± 0.38 ± % R QCD ± 0.28 ± 0.59 dual ± 0.28 miing (%) 0. ± ± 0.07 Sum 693.1±1.2±2.6±1.7±0.1± ±1.4±3.1±2.4±0.2±0.3 19% tat, y, cor, ψ, QCD Zhiqing Zhang (LAL, Oray) 12 /17

13 Contribution in the Region GeV R() e e Hadron KEDR 16 KEDR 17 BES 99 BES 02 BES 06 BES 09 QCD Energy range Data 7.71 ± ± 0.61 pqcd 8.30 ± ± 0.19 Difference 0.59 dual agree < 1σ pqcd evaluated from 4 loop O(α 2 ) quark ma correction Uncertaintie: α, truncation, FOPT/CIPT, m q Zhiqing Zhang (LAL, Oray) 13 /17

14 Contribution from the Charm Reonance Region Cro ection [nb] e e Hadron PLUTO CB BES had, LO 7.29 ± 0.05 ± 0.30 ± % of a µ tat y cor Zhiqing Zhang (LAL, Oray) 14 /17

15 R ee () Hadron R() 6 ρ ω φ J/ ψ ψ(2s) DavierHoeckerMalaecuZhang, ψ ψ 3770 ψ 4160 ψ e e hadron data (HVPTool compilation) BES KEDR pqcd (male) Performed a nontrivial tet: a µ had, LO from R ee agree with that from um of excluive channel Zhiqing Zhang (LAL, Oray) 15 /17

16 Statu of a µ Include other contribution in unit of : QCD NLO: 9.87 ± 0.07; NNLO: 1.24 ± 0.01; LBL:.5 ± 2.6 EW: ± 0. QED: ± a µ = ± 3.4 ± 2.6 ± 0.2 (4.3 tot ) SM prediction Meaurement JN ± 65 HLMNT ± 49 DHMZ ± 49 DHMZ 2017 (thi work) 268 ± 43 BNLE821 (world average) 0 ± 63 BNLE In comparion with the direct meaurement: ± 5.4 ± 3.3 (6.3 tot ) 26.8 ± 7.6 (3.5σ) a µ a µ exp 11 Zhiqing Zhang (LAL, Oray) 16 /17

17 Summary & Perpective a µ had, LO reache 0.5% relative preciion A factor of ~2 improvement over lat ~13 year The preciion i partially limited by the inconitency between different meaurement Need more precie and conitent data et Babar & CMD3 aim for 0.3% yt for π π Important to improve π π π 0 and K K in [12] GeV ma range Uncertainty on LBL will be a next candidate to improve Lattice QCD? Good perpective from direct meaurement Fermilab & JPARC aim for an improvement by a factor ~4 Zhiqing Zhang (LAL, Oray) 17 /17

e + e results from BaBar, status of muon (g-2) prediction and τ mass measurement at BESIII

e + e results from BaBar, status of muon (g-2) prediction and τ mass measurement at BESIII (IHEP-LAL collaboration) Liangliang WANG Outline Introduction to hadronic vacuum polarization ee hadrons results