1 / 17

SUSY loop contributions to the W pair production

SUSY loop contributions to the W pair production. Shinya KANEMURA (Osaka Univ). @LCWS2004 Paris, 21 April 2004. NPB 541 (1999) 50 S.Alam, K.Hagiwara, SK, R.Szalapski, Y.Umeda PRD 62 (2000) 095011 S.Alam, K.Hagiwara, SK, R.Szalapski, Y.Umeda

rio
Download Presentation

SUSY loop contributions to the W pair production

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. SUSY loop contributions to the W pair production Shinya KANEMURA (Osaka Univ) @LCWS2004 Paris, 21 April 2004 NPB 541 (1999) 50S.Alam, K.Hagiwara, SK, R.Szalapski, Y.Umeda PRD 62 (2000) 095011 S.Alam, K.Hagiwara, SK, R.Szalapski, Y.Umeda PRD 68 (2003) 113011 K.Hagiwara, SK, M. Klasen, Y. Umeda

  2. Introduction Precistion data & Study of radiative correction ⇒Information of New Physics The W pair production has been the benchmark process at LEP2, and will continue being so at linear colliders Large production rate Sensitivity to physics of EWSB Radiative correction to this process can be used to prove not only SM but also New Physics models

  3. Alam Barrients-bendezu, Kniehl Hahn SUSY loop effect on sfermions Inos extra Higgs bosons We here discuss contribution of sfermions and charginos/neutralinos Loop calculation for Subtle gauge cancellation appears even at loop level ! ⇒Incomplete treatment of higher order terms leads to artificially large corrections To obtain trustworthy results, we perform tests of numerical calculation program using BRS symmetry, Becchi, Rouet, Stora decoupling property. Appelquist Size of SUSY corrections is evaluated taking into account experimental constraints

  4. Helicity amplitudes

  5. Loop calculation

  6. SUSY loop contributions Sfermion contributions Chargino/neutralino contributions

  7. Test of the loop calculation （１）The BRS symmetry （２）Decouplingproperty Exact decoupling for large Msusy （３）High energy behavior Comparison with analytic formulae Trancate off O(g^6) term

  8. BRS test for one-loop calculation Gounaris et al : Goldstone boson The one-loop form factors are tested except for overall renormalization

  9. This can be used for the test of loop calculation For exact decoupling, we expand the MSSM couplings by the SM couplings and take terms up to

  10. High energy behavior :

  11. Sfermion effects First 2 generation squark effect

  12. Stop-sbottom loop effect

  13. Chargino/neutralino effects

  14. CP phase effect CP odd form factors F4, F6, F7

  15. Phase effect on the helicity amplitudes

  16. Summary • One loop contributions of sfermions and charginos/neutralinos to the helicity amplitudes of • Calculation tested by the • BRS sum rules • Decoupling property • The typical size of the contributions to M(00) • a few times 0.1 % for sfermion effects • O(1%) for chargino/neutralino effects • CP phase effect in the chargino/neutralino sector • At most 0.1% in M(0+)

More Related