Towards the (Mexican) discovery f 2nd class Belle-II

Transcription

1 XV MEXICAN WORKSHOP ON PARTICLES AND FIELDS Mazatlán (Sinaloa) 2-6 November 2015 Towards the (Mexican) discovery f 2nd class Belle-II Dpto. de Física Cinvestav-IPN México DF Collaboration with R. Escribano and S. González-Solís (IFAE & UAB, Barcelona), to appear soon

2 CONTENTS MOTIVATION Relation between pp,ph,ph VFFs Relation between KK,ph,ph SFFs CONCLUSIONS

3 MOTIVATION Non-strange V-A currents can be split into 1st class currents: SCC 2nd class current: Irrespective of the underlying resonance mechanism

4 MOTIVATION Non-strange V-A currents can be split into 1st class currents: SCC 2nd class current: Irrespective of the underlying resonance mechanism Note: There are/have been several attempts to discover SCC in nuclear processes, but they mostly rely on CVC (and SCC should be effects of the order of isospin breaking corrections to CVC) and have large uncertainties. RevModPhys

5 SCC MOTIVATION Irrespective of the underlying resonance mechanism These decay modes should have already been discovered if it was not for the strong bkg

6 SCC MOTIVATION Irrespective of the underlying resonance mechanism These decay modes should have already been discovered if it was not for the strong bkg τ ηπ π 0 ν τ Dumm & Roig Phys.Rev. D86 (2012)

7 SCC MOTIVATION Irrespective of the underlying resonance mechanism The considered processes could provide complementary information to h 3p

8 SCC MOTIVATION Irrespective of the underlying resonance mechanism The considered processes could provide complementary information to h 3p The corresponding suppression of the SM contribution can make NP visible

9 MOTIVATION Enhancement of the dominating SFF: From B tn t Improvable if we know the SFF with < 20% accuracy

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11 Following Gasser & Leutwyler:

12 Following Gasser & Leutwyler: Another FF (F 0 ) is employed instead of F - in order to have both FFs in correspondence with S- (F 0 ) and P-wave (F + ).

13 Following Gasser & Leutwyler: Another FF (F 0 ) is employed instead of F - in order to have both FFs in correspondence with S- (F 0 ) and P-wave (F + ). m

14 Following Gasser & Leutwyler: Another FF (F 0 ) is employed instead of F - in order to have both FFs in correspondence with S- (F 0 ) and P-wave (F + ). m m

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18 All dynamics is encoded in the normalized FFs (Erler)

19 All dynamics is encoded in the normalized FFs (Erler) Isospin-violating quantity explaining the overall suppression of these decays

20 Relation between pp,ph,ph VFFs cpt in the large-n C limit: simultaneous expansion in p 2, m 2 and 1/N C

21 Relation between pp,ph,ph VFFs cpt in the large-n C limit: simultaneous expansion in p 2, m 2 and 1/N C

22 Relation between pp,ph,ph VFFs cpt in the large-n C limit: simultaneous expansion in p 2, m 2 and 1/N C

23 Data-driven ph & ph VFFs

24 Relation between KK,ph,ph SFFs In previous works we showed that a Breit-Wigner description of SFFs fails to account for the data in t K(p/h) n t decays.

25 Relation between KK,ph,ph SFFs In previous works we showed that a Breit-Wigner description of SFFs fails to account for the data in t K(p/h) n t decays. This is not surprising since BWs violate analyticity and unitarity and do not comply with chiral symmetry requirements.

26 Relation between KK,ph,ph SFFs In previous works we showed that a Breit-Wigner description of SFFs fails to account for the data in t K(p/h) n t decays. This is not surprising since BWs violate analyticity and unitarity and do not comply with chiral symmetry requirements. Although theory says BWs should not be applied, sometimes they are an easy solution fo the experimentalists.

27 Relation between KK,ph,ph SFFs In previous works we showed that a Breit-Wigner description of SFFs fails to account for the data in t K(p/h) n t decays. This is not surprising since BWs violate analyticity and unitarity and do not comply with chiral symmetry requirements. Although theory says BWs should not be applied, sometimes they are an easy solution fo the experimentalists. That is why we decided to start our analyses with them (again).

28 Relation between KK,ph,ph SFFs

29 Relation between KK,ph,ph SFFs (Brodsky-Lepage) Real part of the loop neglected Violation of analyticity

30 Relation between KK,ph,ph SFFs We have also considered a two-resonance BW SFF Now both normalized FFs differ!

31 Relation between KK,ph,ph SFFs

32 Relation between KK,ph,ph SFFs Errors known, correlations unknown!

33 Relation between KK,ph,ph SFFs

34 Relation between KK,ph,ph SFFs (Brodsky-Lepage)

35 Relation between KK,ph,ph SFFs

36 Relation between KK,ph,ph SFFs

37 Relation between KK,ph,ph SFFs Very different normalized FFs!

38 Relation between KK,ph,ph SFFs traditional iterative solution

39 Relation between KK,ph,ph SFFs Closed-form solution A closed-form solution is much less time-consuming than the traditional iterative method, which is great for fits and MC generators (TAUOLA) O. Shekhovtsova, T. Przedzinski, P. Roig & Z. Was. Phys.Rev. D86 (2012)

40 Relation between KK,ph,ph SFFs Closed-form solution Crucial coupled channels corrections! Very different normalized FFs!

41 Relation between KK,ph,ph SFFs We can also consider coupling ph & ph to KK Crucial coupled channels corrections! Closed-form solution Strong effect of coupling to KK! a 0 (980) as KK molecule or tetraquark Very different normalized FFs!

42 Relation between KK,ph,ph SFFs Straightforward generalization of 2-coupled channels case (closed-form solution)

43 Relation between KK,ph,ph SFFs

44 Relation between KK,ph,ph SFFs

45 Relation between KK,ph,ph SFFs

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48 Errors due to p-h-h mixing Towards the discovery of 2nd class Belle-II

49 Meaningless uncorrelated error analysis Towards the discovery of 2nd class Belle-II

50 Predictions for ph Towards the discovery of 2nd class Belle-II

51 Science-fiction measurement? Towards the discovery of 2nd class Belle-II Same FF s but they are real in h l3 while complex in t decays In h decays SFF is suppressed by m l2, while it dominates the corresponding t decays 90% CL

52 Science-fiction measurement? Towards the discovery of 2nd class Belle-II

53 CONCLUSIONS We improve the SM description of the t ph ( ) n t decays. VFF predictions are sharp, while (dominating) SFF s have large uncertainties.

54 CONCLUSIONS We improve the SM description of the t ph ( ) n t decays. VFF predictions are sharp, while (dominating) SFF s have large uncertainties. Discovery of (SM) 2nd class currents through these decay modes should be Belle-II.

55 CONCLUSIONS We improve the SM description of the t ph ( ) n t decays. VFF predictions are sharp, while (dominating) SFF s have large uncertainties. Discovery of (SM) 2nd class currents through these decay modes should be Belle-II. SU(2) New Physics signals may show up.

56 CONCLUSIONS We improve the SM description of the t ph ( ) n t decays. VFF predictions are sharp, while (dominating) SFF s have large uncertainties. Discovery of (SM) 2nd class currents through these decay modes should be Belle-II. SU(2) New Physics signals may show up. The search for these decays will be driven by the Mexican node of the Belle-II Collaboration (Michel Hernández, Eduard & Gabriel s student).

57 CONCLUSIONS We improve the SM description of the t ph ( ) n t decays. VFF predictions are sharp, while (dominating) SFF s have large uncertainties. Discovery of (SM) 2nd class currents through these decay modes should be Belle-II. SU(2) New Physics signals may show up. The search for these decays will be leaded by the Mexican node of the Belle-II Collaboration.

58 CONCLUSIONS We improve the SM description of the t ph ( ) n t decays. VFF predictions are sharp, while (dominating) SFF s have large uncertainties. Discovery of (SM) 2nd class currents through these decay modes should be Belle-II. SU(2) New Physics signals may show up. The search for these decays will be driven by the Mexican node of the Belle-II Collaboration. México is also contributing coding the relevant SM FFs in TAUOLA and predicting the most important SM bkg (t ph ( ) gn t Adolfo Guevara, Gabriel & PR).

59 ANUNCIO Se oferta un posdoc de dos años (1+1) asociado al proyecto de Ciencia Básica del Dr. Gabriel López Castro (Cinvestav, México DF) en el área de Física de sabor: fenomenología para comenzar en Abril de La convocatoria se realizará próximamente a través de las listas de correo de la DPyC y RED-FAE.