Monte Carlo generators for hadron physics: updates on PHOKHARA and EKHARA generators. Messina, October 2016

Transcription

1 Monte Carlo generators for hadron physics: updates on PHOKHARA and EKHARA generators H. CZYŻ, IF, UŚ, Katowice, Poland International Symposium, Advances in Dark Matter and Particle Physics Messina, October 2016

2 Outline PHOKHARA and EKHARA in brief Recent developments in PHOKHARA χ ci production- Sz. Tracz Missing radiative corrections: FSR modeling Pentaboxes Recent developments in EKHARA χ ci production Final remarks UŚ, Katowice, PHOKHARA and EKHARA updates 2

3 Motivation: (g 2) µ (g 2) SM µ = ± 4.2(had) ± 2.6(L L) ± 0.2 (g 2) exp µ = ± 5.4 ± 3.3 EXP SM = 28.7 ± 8.0 M.Davier,A.Hoecker,B.Malaescu,Z.Zhang,Eur.Phys.J.C71 (2011) Muon g-2 Collaboration (G.W. Bennett et al.), Phys. Rev. D 73, (2006) [hep-ex/ ]. UŚ, Katowice, PHOKHARA and EKHARA updates 3

4 anatomy of (g 2) µ a had µ = a had,lo µ + a had,ho µ + a had,lbl µ UŚ, Katowice, PHOKHARA and EKHARA updates 4

5 The reason we need R(s) a had,lo µ = α2 3π 2 m 2 π ds s K(s) R(s) R(s) = σ(e+ e hadrons) σ point One has to measure : σ(e + e hadrons) UŚ, Katowice, PHOKHARA and EKHARA updates 5

6 ahad LO µ Hagiwara et al. J.Phys. G38 (2011) UŚ, Katowice, PHOKHARA and EKHARA updates 6

7 THE RADIATIVE RETURN METHOD dσ(e + e hadrons + γ(isr)) = H(Q 2,θ γ ) dσ(e + e hadrons)(s = Q 2 ) measurement of R(s) over the full range of energies, from threshold up to s large luminosities of factories compensate α/π from photon radiation radiative corrections essential (NLO,...) High precision measurement of the hadronic cross-section at meson-factories UŚ, Katowice, PHOKHARA and EKHARA updates 7

8 PHOKHARA MC generator EVA: e + e π + π γ tagged photon (θ γ > θ cut ) ISR at LO + Structure Function FSR: point-like pions e + e 4π + γ [Binner et al.] ISR at LO + Structure Function [Czyż, Kühn,2000] F. Campanario, H.C., J. Gluza, PHOKHARA 9.2: π + π, µ + µ, 4π, NN, 3π, KK,Λ Λ J/ψ,ψ(2S), χ c1,χ c2 ISR at NLO: virtual corrections to one photon events and two photon emission at tree level γ γ 2 γ 2 γ + + A. Grzelińska, M. Gunia, J. H. Kühn, E. Nowak-Kubat, T. Riemann, G. Rodrigo, Sz. Tracz, A. Wapienik, V. Yundin, D. Zhuridov FSR at NLO:π + π, µ + µ,k + K, pp tagged or untagged photons e + e hadrons (muons) ISR at NNLO Modular structure UŚ, Katowice, PHOKHARA and EKHARA updates 8

9 Photon-photon interactions UŚ, Katowice, PHOKHARA and EKHARA updates 9

10 EKHARA MC generator 1.0: e + e π + π e + e background to e + e π + π γ Henryk Czyż, Elżbieta Nowak-Kubat, Phys. Lett. B 634, 493 (2006), EKHARA 2.1: π + π, π 0, η, η 2.1: e + e π 0 e + e Henryk Czyż, Sergiy Ivashyn, Com.Phys.Commun. 182(2011) 1338 p 2 p 1 q 2 p 2 Q q 1 p 1 Modular structure Q q 2 q 1 + A. Korchin, O. Shekhovtsova; Phys.Rev. D85 (2012) radiative correction to be included soon ekhara/ UŚ, Katowice, PHOKHARA and EKHARA updates 10

11 Phys.Lett. B753 (2016) 629 BESIII new results UŚ, Katowice, PHOKHARA and EKHARA updates 11

12 Phys.Lett. B753 (2016) 629 BESIII new results UŚ, Katowice, PHOKHARA and EKHARA updates 12

13 PENTABOXES For muons only, for pions in progress UŚ, Katowice, PHOKHARA and EKHARA updates 13

14 Size of the new corrections JHEP 1402 (2014) 114 UŚ, Katowice, PHOKHARA and EKHARA updates 14

15 Size of the pentaboxes JHEP 1402 (2014) 114 UŚ, Katowice, PHOKHARA and EKHARA updates 15

16 PENTABOXES-pions The team: F. Campanario, (Karlsruhe) H.C., J. Gluza, T. Jeliński, Sz. Tracz, D. Zhuridov (Katowice) T. Riemann (DESY, Zeuthen) The task: + UŚ, Katowice, PHOKHARA and EKHARA updates 16

17 ¾¼ Æ ½ ¼ Æ ¼ Æ ½ ¼ Æ FSR at NLO, PHOKHARA ½ ¾ ½ ½ ËÆÄǵ ÁËÊÆÄǵ Á É ¾ ½ ¾ É ¼ ½ ¼ ¼ ¼ µ Ô = GeV b ¼ ¼ ¼ ½ ½ ½ ½ ¾ ½ ¼ ¼ ¼ ¼ ¾ ¼ É ¾ Î ¾ µ UŚ, Katowice, PHOKHARA and EKHARA updates 17

18 PENTABOXES-pions Preliminary results for ISR pentaboxes (sqed): E= 1.02 GeV; penta/born = KLOE -tag; penta/born = E= GeV; penta/born = BaBar; penta/born = UŚ, Katowice, PHOKHARA and EKHARA updates 18

19 χ c in EKHARA H.C., P.Kisza, in preparation UŚ, Katowice, PHOKHARA and EKHARA updates 19

20 χ c in EKHARA BELLE2: e + e e + e χ ci χ c Number of events (Luminosity = 50ab 1 ) H.C., P.Kisza, in preparation UŚ, Katowice, PHOKHARA and EKHARA updates 20

21 χ c in EKHARA BELLE2: e + e e + e χ ci J/ψ( µ + µ )γ 20 < θ γ,θ µ < 160 M 10Γ < inv. mass < M + 10Γ χ c Number of events (Luminosity = 50ab 1 ) H.C., P.Kisza, in preparation UŚ, Katowice, PHOKHARA and EKHARA updates 21

22 χ c in EKHARA e + e e + e χ c0 ( J/ψ( µ + µ )γ e + e e + e χ c1 ( J/ψ( µ + µ )γ N events 100 N events q 2 (GeV 2 ) q 2 (GeV 2 ) H.C., P.Kisza, in preparation UŚ, Katowice, PHOKHARA and EKHARA updates 22

23 Concluding remarks slow but continuous progress observed in quest for precision in low energy hadronic physics serious challenges in the forthcoming years radiative corrections, form factors modelling... promising perspectives of new measurements at BELLE2, BES-III, VEPP2000, KLOE2, UŚ, Katowice, PHOKHARA and EKHARA updates 23