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Status and progress of the HFLAV-Tau group activities Alberto - - PowerPoint PPT Presentation

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Status and progress of the HFLAV-Tau group activities Alberto Lusiani Scuola Normale Superiore and INFN, sezione di Pisa Status and progress of the HFLAV-Tau group activities Outline 1 Introduction 2 Tau Branching Fractions Fit 3 Lepton

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Status and progress of the HFLAV-Tau group activities

Alberto Lusiani

Scuola Normale Superiore and INFN, sezione di Pisa

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Status and progress of the HFLAV-Tau group activities

Outline

1 Introduction 2 Tau Branching Fractions Fit 3 Lepton Universality 4 Determination of |Vus| from Tau Decays 5 Further investigations on |Vus| from fi → s inclusive 6 HFLAV Tau LVF combinations 7 Summary

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 2 / 46

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Status and progress of the HFLAV-Tau group activities Introduction

HFLAV Tau sub-group

(HFLAV = Heavy Heavy Flavour Averaging Group) (new acronym since 2017)

I Tau sub-group established since 2008, http://www.slac.stanford.edu/xorg/hflav/tau/

membership BABAR • Swagato Banerjee (Victoria → Louisville)

  • A. L. (convener)
  • J. Michael Roney (Victoria)

Belle

  • Kiyoshi Hayasaka (Nagoya → Niigata)
  • Hisaki Hayashii (Nara)
  • Boris Shwartz (Budker)

LHCb • Marcin Chrząszcz (Zürich / Cracow) (since 2014)

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 3 / 46

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Status and progress of the HFLAV-Tau group activities Introduction

Introduction

HFLAV-Tau goals

I provide up-to-date tau lepton properties world averages

(especially when one can improve over PDG standard averages)

I exploit at best all relevant experimental information I provide some useful elaborations of tau data

(e.g., charged weak current lepton universality, |Vus| computed from tau data) recent history 2014 • summer 2014 HFLAV report (arXiv preprint) 2016 • summer 2016 HFLAV report (arXiv preprint)

  • PDG tau branching fraction fit provided by HFLAV-Tau group since 2016
  • PDG tau BRs mini-review since 2016 co-authored by 2 HFLAV members

2017 • acronym changed from HFAG to HFLAV

  • spring 2017 HFLAV report submitted for refereed publication
  • very minor refinements w.r.t. summer 2016 release

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 4 / 46

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Status and progress of the HFLAV-Tau group activities

Tau Branching Fractions Fit

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 5 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

HFLAV Tau Branching Fraction Fit Features

I use published statistical and systematic correlations I aim to avoid error scale factors as used by PDG, including relevant systematic effects I global minimum ffl2 fit using constraint equations (see later)

systematic dependencies of results from external parameters

I experimental measurements typically depend on external parameters

[e.g., ff(e+e− → fi +fi −), ” and ! branching fractions, other fi branching fractions]

I identify dependencies from external parameters, typically from systematics tables I update results values and uncertainties according to updates of external parameters

common systematics across different experimental results

I two or more results may depend on the same external parameters

(also across different publications and different experiments) e.g.: may depend on estimated integrated luminosity, ff(e+e− → fi +fi −)

I account for statistical correlations induced by common systematics Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 6 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

HFLAV Tau Branching Fraction Fit Features (2)

example of constraint equations

I B(fi → h) = B(fi → ı) + B(fi → K)

(h = ı; K)

I B(fi −→ı−ı+ı−) = B[fi −→ı−ı+ı− (ex: KS→ı+ı−)] + B(fi −→ı−KS) · B(KS→ı+ı−) I

»

B(fi → —¯ ) B(fi → e¯ )

–

= [B(fi → —¯ )] [B(fi → e¯ )]

I unitarity constraint (not used for HFLAV-Tau fit, used for PDG BR fits)

properties of PDG fit before 2016 that differ from HFLAV fit

I unitarity constraint I does not usually consider effects of external parameters dependencies I uses error scale factors (complex procedure used for scale factors in global fit) Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 7 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

Main Changes from 2014 to 2016-2017

I no new experimental input (there were several in the 2014 report) I removed two old preliminary results I Γ35 = B(fi → ıK0 S), BABAR, ICHEP 2008 I Γ40 = B(fi → ıK0 Sı0), BABAR, DPF 2009 I removed result B[fi → K0 S(particles)−], Belle, 2014 I information in the paper does not allow computing consistent correlations with the

  • ther esclusive results in the same paper; the 2014 report included some inconsistent

estimate, which made the results covariance matrix negative-definite

I ALEPH 1998 Γ46 (fi − → ı−K0 ¯

K0fi) has been removed because 100% correlated with

  • ther esclusive results

I several minor constraint imperfections were fixed I all fixes have negligible effects on |Vus|, lepton-universality tests, . . . Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 8 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

Tau Branching Fractions Fit results

I 170 measurements, 88 constraint equations I fit 135 quantities: 47 BRs, 88 derived quantities (ratios of linear combinations of BRs) I ffl2=d.o.f. = 137=123,

CL = 17:79% (was 16.45% in 2014)

I 5.44 error scale factor for inconsistent BABAR and Belle B(fi −→K−K−K+fi) as in 2014 I consistent with unitarity within 0.1% uncertainty, residual = (0:03 ± 0:10)% Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 9 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

2016 fit inputs results by experiment

experiment number of results ALEPH 39 CLEO 35 BaBar 23 OPAL 19 Belle 15 DELPHI 14 L3 11 CLEO3 6 TPC 3 ARGUS 2 HRS 2 CELLO 1

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 10 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

HFLAV spring 2017 basis modes

B (fi → : : :) HFLAV spring 2017 —−¯ —fi 17:3917 ± 0:0396 e−¯ efi 17:8162 ± 0:0410 ı−fi 10:8103 ± 0:0526 K−fi 0:6960 ± 0:0096 ı−ı0fi 25:5023 ± 0:0918 K−ı0fi 0:4327 ± 0:0149 ı−2ı0fi (ex. K0) 9:2424 ± 0:0997 K−2ı0fi (ex. K0) 0:0640 ± 0:0220 ı−3ı0fi (ex. K0) 1:0287 ± 0:0749 K−3ı0fi (ex. K0; ”) 0:0428 ± 0:0216 h−4ı0fi (ex. K0; ”) 0:1099 ± 0:0391 ı− ¯ K0fi 0:8386 ± 0:0141 K−K0fi 0:1479 ± 0:0053 ı− ¯ K0ı0fi 0:3812 ± 0:0129 K−ı0K0fi 0:1502 ± 0:0071 ı− ¯ K0ı0ı0fi (ex. K0) 0:0234 ± 0:0231 ı−K0

SK0 Sfi

0:0233 ± 0:0007 ı−K0

SK0 Lfi

0:1047 ± 0:0247 ı−ı0K0

SK0 Sfi

0:0018 ± 0:0002 ı−ı0K0

SK0 Lfi

0:0318 ± 0:0119 ¯ K0h−h−h+fi 0:0222 ± 0:0202 ı−ı−ı+fi (ex. K0; !) 8:9704 ± 0:0515 ı−ı−ı+ı0fi (ex. K0; !) 2:7694 ± 0:0711 h−h−h+2ı0fi (ex. K0; !; ”) 0:0976 ± 0:0355 B (fi → : : :) HFLAV spring 2017 ı−K−K+fi 0:1434 ± 0:0027 ı−K−K+ı0fi 0:0061 ± 0:0018 ı−ı0”fi 0:1386 ± 0:0072 K−”fi 0:0155 ± 0:0008 K−ı0”fi 0:0048 ± 0:0012 ı− ¯ K0”fi 0:0094 ± 0:0015 ı−ı+ı−”fi (ex. K0) 0:0218 ± 0:0013 K−!fi 0:0410 ± 0:0092 h−ı0!fi 0:4058 ± 0:0419 K−ffifi 0:0044 ± 0:0016 ı−!fi 1:9544 ± 0:0647 K−ı−ı+fi (ex. K0; !) 0:2923 ± 0:0067 K−ı−ı+ı0fi (ex. K0; !; ”) 0:0410 ± 0:0143 a−

1 (→ ı−‚)fi

0:0400 ± 0:0200 ı−2ı0!fi (ex. K0) 0:0071 ± 0:0016 2ı−ı+3ı0fi (ex. K0; ”; !; f1) 0:0013 ± 0:0027 3ı−2ı+fi (ex. K0; !; f1) 0:0768 ± 0:0030 K−2ı−2ı+fi (ex. K0) 0:0001 ± 0:0001 2ı−ı+!fi (ex. K0) 0:0084 ± 0:0006 3ı−2ı+ı0fi (ex. K0; ”; !; f1) 0:0038 ± 0:0009 K−2ı−2ı+ı0fi (ex. K0) 0:0001 ± 0:0001 ı−f1fi (f1 → 2ı−2ı+) 0:0052 ± 0:0004 ı−2ı0”fi 0:0193 ± 0:0038 1 − ΓAll 0:0355 ± 0:1031

note: a linear combination sums up to 1

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 11 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

Measurement pulls, pulls probability - HFLAV spring 2017, no scaling

2 4 6 8 10 12 14 16 18 20 22 24 −6 −5 −4 −3 −2 −1 1 2 3 4 5

Pull Number of measurements

2 4 6 8 10 12 14 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Probability Number of measurements I two outliers: BABAR and Belle B(fi → K−K−K+fi) results I (pull probabilities expressed as n. of Gaussian sigma’s) Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 12 / 46

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Status and progress of the HFLAV-Tau group activities Tau Branching Fractions Fit

B-factories tend to measure lower BFs

I first noted in PDG tau branching fraction review I compared fit results in the same fit framework with and without B-factories results

BABAR results vs. non-BF fit results

BaBar

1 2 3 4 −3 −2 −1 1 2 3

standard deviations number of measurements

Belle results vs. non-BF fit results

Belle

1 2 3 4 −3 −2 −1 1 2 3

standard deviations number of measurements

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 13 / 46

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Status and progress of the HFLAV-Tau group activities

Lepton Universality

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 14 / 46

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Status and progress of the HFLAV-Tau group activities Lepton Universality

Lepton universality - HFLAV spring 2017

Standard Model for leptons –,  = e; —; fi (Marciano 1988) Γ[– → –¯ (‚)] = Γ– = Γ–B– = B– fi– = G–Gm5

–

192ı3 f ` m2

=m2 –

´

R–

W R– ‚ ;

where G– = g 2

–

4 √ 2M2

W

f (x) = 1 − 8x + 8x3 − x4 − 12x2lnx f– = f ` m2

=m2 –

´

R–

W = 1 + 3

5 m2

–

M2

W

+ 9 5 m2

M2

W

R–

‚ = 1 + ¸(m–)

2ı

“ 25

4 − ı2”

Tests of lepton universality from ratios of above partial widths:

„

gfi g—

«

=

s

Bfie B—e fi—m5

—f—eR— ‚ R— W

fifim5

fiffieRfi ‚ Rfi W

= 1:0010 ± 0:0015 =

r

Bfie BSM

fie

„

gfi ge

«

=

s

Bfi— B—e fi—m5

—f—eR— ‚ R— W

fifim5

fiffi—Rfi ‚ Rfi W

= 1:0029 ± 0:0015

fashionable ∼2ff lepton universality violation

=

s

Bfi— BSM

fi—

„

g— ge

«

=

r

Bfi— Bfie ffie ffi— = 1:0019 ± 0:0014

I precision: 0:20−0:23% pre-B-Factories ⇒ 0:14−0:15% today

thanks essentially to the Belle tau lifetime measurement, PRL 112 (2014) 031801

I Rfi ‚ = 1 − 43:2 · 10−4 and R— ‚ = 1 − 42:4 · 10−4 (Marciano 1988),

MW from PDG 2015

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 15 / 46

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Status and progress of the HFLAV-Tau group activities Lepton Universality

Lepton Universality tests with hadron decays - HFLAV spring 2017

Standard Model:

„

gfi g—

«2

= B(fi → hfi) B(h → —¯ —) 2mhm2

—fih

(1 + ‹h)m3

fififi

„

1 − m2

—=m2 h

1 − m2

h=m2 fi

«2

(h = ı or K)

  • rad. corr. ‹ı = (0:16 ± 0:14)%,

‹K = (0:90 ± 0:22)% (Decker 1994)

„

gfi g—

«

ı

= 0:9961 ± 0:0027 ;

„

gfi g—

«

K

= 0:9860 ± 0:0070 : fashionable ∼2ff lepton universality violations (electron tests less precise because h → e decays are helicity-suppressed) Averaging the three gfi=g— ratios:

„

gfi g—

«

fi+ı+K

= 1:0000 ± 0:0014 ; (accounting for statistical correlations)

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 16 / 46

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Status and progress of the HFLAV-Tau group activities Lepton Universality

Lepton universality - HFLAV spring 2017 (2)

Canonical tau lepton universality test plot

  • HFLAV

Spring 2017

0.1770 0.1775 0.1780 0.1785 0.1790 289 290 291 292

ττ(fs) B′(τ → eνν) I Γ(fi → e¯

) Γ(— → e¯ ) = B′(fi → e¯ ) B(— → e¯ ) = fifi fi— m5

fi

m5

—

ffieRfi

‚Rfi W

f—eR—

‚ R— W I B′(fi → e¯

) computed averaging:

I Be(e) = B(fi → e¯

)

I Be(—) = B(fi → —¯

) · ffie=ffi—

inputs

PDG 2015 and HFLAV-Tau spring 2017, other details listed in HFLAV 2016 report

Universality test uncertainty now limited by leptonic BRs input ∆input ∆test fifi 0.090% 0.18% Bfi→—;e 0.115% 0.23% mfi 0.022% 0.009%

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 17 / 46

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Status and progress of the HFLAV-Tau group activities Lepton Universality

Universality improved B(fi → e¯ ) and Rhad - HFLAV spring 2017

Universality improved B(fi → e¯ )

I (M. Davier, 2005): assume SM to improve Be = B(fi → e¯

efi) averaging: Be(e) = Be; Be(—) = B— · ffie=ffi— Be(fifi) = fifi fi— m5

fi

m5

—

ffieRfi

‚Rfi W

f—eR—

‚ R— W I Buniv e

= (17:815 ± 0:023)%

HFLAV spring 2017 fit

Rhad = Γ(fi → hadrons)=Γuniv(fi → e¯ ) = B(fi → hadrons)=Buniv(fi → e¯ )

I Rhad = Bhadrons

Buniv

e

= 3:6349 ± 0:0082

HFLAV spring 2017 fit I Rhad(lepton univ.) =

1 − Buniv

e

− ffi—=ffie · Buniv

e

Buniv

e

= 3:6406 ± 0:0072

HFLAV spring 2017 fit I Rhad(lepton only) =

1 − Be − B— Buniv

e

= 3:637 ± 0:011

HFLAV spring 2017 fit Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 18 / 46

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Status and progress of the HFLAV-Tau group activities

Determination of |Vus| from Tau Decays

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 19 / 46

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Status and progress of the HFLAV-Tau group activities Determination of ˛

˛Vus ˛ ˛ from Tau Decays

Determination of |Vus| from experimental data

from kaon decays

I Γ(K → ı‘¯

‘[‚]) = G2

F m5 K

192ı3 C2

K SK EW

`

|Vus|f Kı

+

(0)´2 I‘

K

`

1 + ‹K‘

EM + ‹Kı SU(2)

´2

I

Γ(K± → ‘±) Γ(ı± → ‘±) = |Vus|2 |Vud|2 f 2

K

f 2

ı

mK(1 − m2

‘=m2 K)2

mı(1 − m2

‘=m2 ı)2 (1 + ‹EM)

from tau decays

I

R(fi → Xstrange) |Vus|2 − R(fi → Xnon-strange) |Vud|2 = ‹Rfi;SU3 breaking, “fi → s inclusive” method [R(fi → X) = Γ(fi → X)=Γ(fi → e)]

I

B(fi − → K−fi ) B(fi − → ı−fi ) = f 2

K|Vus|2

f 2

ı |Vud|2

`

1 − m2

K=m2 fi

´2 `

1 − m2

ı=m2 fi

´2

rLD(fi − → K−fi ) rLD(fi − → ı−fi )

I Γ(fi → ¯

Kıfi [‚]) = G2

F m5 fi

96ı3 C2

K SfiKı EW

`

|Vus|f Kı

+

(0)´2 Ifi

K

`

1 + ‹Kfi

EM + ˜

‹Kı

SU(2)

´2

I only fi → s inclusive method does not require form factors from lattice QCD

and therefore has theory systematics uncorrelated to lattice QCD form factors

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 20 / 46

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Status and progress of the HFLAV-Tau group activities Determination of ˛

˛Vus ˛ ˛ from Tau Decays

“fi → s inclusive” |Vus| determination

R(fi → Xstrange) |Vus|2 − R(fi → Xnon-strange) |Vud|2 = ‹Rfi;SU3 breaking ‹Rfi;SU3 breaking can be computed with OPE techniques

I finite-energy sum rules (FESR) with

either fixed-order (FOPT) or contour-improved (CIPT) prescriptions

I strong dependence from ms I problematic convergence requires special treatment I non-pert. terms fitted and/or estimated using tau spectral functions moments I assumptions on D>4 OPE contributions

get ms from world average and compute |Vus|

I Gamiz, Jamin, Pich, Prades, Schwab, JHEP 01 (2003) 06, PRL 94 (2005) 011803, I Maltman, 1011.6391 [hep-ph] I Maltman, Lattice 2015, 1510.06954 [hep-ph]

(uses tau spectral functions)

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 21 / 46

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Status and progress of the HFLAV-Tau group activities Determination of ˛

˛Vus ˛ ˛ from Tau Decays

Tau branching fractions to strange final states, HFLAV spring 2017

Branching fraction HFLAV spring 2017 fit K−fi 0:6960 ± 0:0096 K−ı0fi 0:4327 ± 0:0149 K−2ı0fi (ex. K0) 0:0640 ± 0:0220 K−3ı0fi (ex. K0; ”) 0:0428 ± 0:0216 ı− ¯ K0fi 0:8386 ± 0:0141 ı− ¯ K0ı0fi 0:3812 ± 0:0129 ı− ¯ K0ı0ı0fi (ex. K0) 0:0234 ± 0:0231 ¯ K0h−h−h+fi 0:0222 ± 0:0202 K−”fi 0:0155 ± 0:0008 K−ı0”fi 0:0048 ± 0:0012 ı− ¯ K0”fi 0:0094 ± 0:0015 K−!fi 0:0410 ± 0:0092 K−ffifi (ffi → K+K−) 0:0022 ± 0:0008 K−ffifi (ffi → K0

SK0 L)

0:0015 ± 0:0006 K−ı−ı+fi (ex. K0; !) 0:2923 ± 0:0067 K−ı−ı+ı0fi (ex. K0; !; ”) 0:0410 ± 0:0143 K−2ı−2ı+fi (ex. K0) 0:0001 ± 0:0001 K−2ı−2ı+ı0fi (ex. K0) 0:0001 ± 0:0001 X−

s fi

2:9087 ± 0:0482

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 22 / 46

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Status and progress of the HFLAV-Tau group activities Determination of ˛

˛Vus ˛ ˛ from Tau Decays

|Vus| results

|

us

|V

0.22 0.225 , PDG 2016

l3

K 0.0010 ± 0.2237 , PDG 2016

l2

K 0.0007 ± 0.2254 CKM unitarity, PDG 2016 0.0009 ± 0.2258 s incl., HFLAV Spring 2017 → τ 0.0021 ± 0.2186 , HFLAV Spring 2017 ν π → τ / ν K → τ 0.0018 ± 0.2236 average, HFLAV Spring 2017 τ 0.0015 ± 0.2216

HFLAV

Spring 2017 I fi → s inclusive vs. CKM unitarity discrepancy: −3:1 ff I no significant change since beginning of HFLAV-Tau (2010) I ms = 95:00±5:00 MeV (PDG 2015) and ‹Rfi = 0:242±0:032 (arXiv:hep-ph/0612154)

(chosen estimate of ‹Rfi with intermediate uncertainty)

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 23 / 46

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Status and progress of the HFLAV-Tau group activities

Further investigations on |Vus| from fi → s inclusive

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 24 / 46

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Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

|Vus| from fi → s inclusive by K. Maltman et al. (2015→)

I arXiv:1510.06954 [hep-ph], arXiv:1511.08514 [hep-ph], arXiv:1702.01767 [hep-ph]

modifications of method

I uses spectral functions of fi → Xs decays

⇒ improves reliability of estimated theory uncertainty modifications of inputs

I replaces HFLAV B(fi → Kı0) with value from A. Adametz PHD thesis (2011)

(inspirehep.net/record/946707), BABAR work-in-progress, never made public by BABAR

I replaces HFLAV B(fi → K) with indirect calculation using B(K → ‘) Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 25 / 46

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Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

|Vus| from fi → s inclusive by K. Maltman et al. (2015→)

|

us

|V

0.22 0.225 CKM unitarity, PDG 2016 0.0009 ± 0.2258 s incl., HFLAV Spring 2017 → τ 0.0021 ± 0.2186 with Adametz '11 ν π K → τ & repl. 0.0022 ± 0.2211 using kaons ν K → τ & also repl. 0.0021 ± 0.2218 s incl., Maltman 2017 → τ 0.0004 ± 0.0022 ± 0.2229

HFLAV

Spring 2017 I using traditional fi → s inclusive method, reproduce |Vus| shifts due to change of inputs

⇒ reduction of discrepancy mostly due to change of inputs

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 26 / 46

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Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

Tau BRs measurements in A. Adametz PHD thesis (2011)

I based on full BABAR dataset, but for BABAR they are still “work in progress”, never released I authors became essentially unavailable before completing internal BABAR review I now plan to bring to publication (thanks also to funds from Scuola Normale) I use data for reconstruction efficiencies, more refined than BABAR 2007 B(fi → Kı0)

Simultaneous measurement of fi → K nı0 n = 0; 1; 2; 3 fi → ı nı0 n = 3; 4 ı0 efficiency & cross-check from fi → ı nı0 n = 0; 1; 2 ı & K PID efficiency from fi − → ı−ı−ı+ pure ı+ fi − → ı−K+K− pure K−

e/μ τ τ π/K N π0

ν ν ν

Dataset ∼full BABAR data sample, ∼430fb−1

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 27 / 46

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Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

HFLAV |Vus| from fi → s inclusive uncertainties budget (%)

ı− ¯ K0ı0ı0fi (ex. K0) 0.3963 K−2ı0fi (ex. K0) 0.3789 K−3ı0fi (ex. K0; ”) 0.3715 ¯ K0h−h−h+fi 0.3478 K−ı0fi 0.2561 K−ı−ı+ı0fi (ex. K0; !; ”) 0.2456 ı− ¯ K0fi 0.2424 ı− ¯ K0ı0fi 0.2219 K−fi 0.1646 K−!fi 0.1585 K−ı−ı+fi (ex. K0; !) 0.1157 ı− ¯ K0”fi 0.0256 K−ı0”fi 0.0200 K−”fi 0.0138 K−ffifi (ffi → K+K−) 0.0138 K−ffifi (ffi → K0

SK0 L)

0.0096 K−2ı−2ı+fi (ex. K0) 0.0021 K−2ı−2ı+ı0fi (ex. K0) 0.0010 fi → non-strange 0.0896 Buniv

e

0.0045 theory 0.4722

magenta BRs measured in Adametz thesis

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 28 / 46

slide-29
SLIDE 29

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

  • A. Adametz 2011 thesis B(fi → K)

) [%]

τ

ν

  • K

→

  • τ

B(

0.6 0.7 0.8 CLEO 1994 0.090 ± 0.070 ± 0.660 DELPHI 1994 0.180 ± 0.850 ALEPH 1999 0.029 ± 0.696 OPAL 2001 0.029 ± 0.027 ± 0.658 Adametz 2011 0.016 ± 0.003 ± 0.710 HFLAV Spring 2017 0.010 ± 0.696 HFLAV + Adametz 2011 0.008 ± 0.699

AL in progress

JUN 2017

I HFLAV average dominated by BABAR measurement of B(fi → K)=B(fi → e¯

) (not reported in the plot)

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 29 / 46

slide-30
SLIDE 30

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

  • A. Adametz 2011 thesis B(fi → Kı0)

) [%]

τ

ν π

  • K

→

  • τ

B(

0.4 0.5 0.6 CLEO 1994 0.070 ± 0.100 ± 0.510 ALEPH 1999 0.035 ± 0.444 OPAL 2004 0.023 ± 0.059 ± 0.471 BaBar 2007 0.018 ± 0.003 ± 0.416 Adametz 2011 0.014 ± 0.002 ± 0.500 , JHEP 10 (2013) 76 ν l π → from K 0.018 ± 0.471 HFLAV Spring 2017 0.015 ± 0.433 HFLAV + Adametz 2011 0.008 ± 0.484

AL in progress

JUN 2017

I in “HFLAV + Adametz 2011”, BABAR 2007 result is superseded by Adametz 2011 result I for comparison, show also B(fi → Kı0) indirect determination from B(K → ‘ı0¯

)

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 30 / 46

slide-31
SLIDE 31

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

  • A. Adametz 2011 thesis B(fi → K2ı0)

]

  • 4

10 × )) [ (ex. K

τ

ν π 2

  • K

→

  • τ

B(

2 4 6 8 CLEO 1994 3.000 ± 10.000 ± 9.000 ALEPH 1999 2.500 ± 5.600 Adametz 2011 0.323 ± 0.144 ± 5.654 HFLAV Spring 2017 2.204 ± 6.398 HFLAV + Adametz 2011 0.266 ± 5.300

AL in progress

JUN 2017

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 31 / 46

slide-32
SLIDE 32

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

  • A. Adametz 2011 thesis B(fi → K3ı0)

]

  • 4

10 × )) [ η , (ex. K

τ

ν π 3

  • K

→

  • τ

B(

2 4 6 ALEPH 1999 2.371 ± 3.700 Adametz 2011 0.375 ± 0.279 ± 1.642 HFLAV Spring 2017 2.161 ± 4.284 HFLAV + Adametz 2011 0.432 ± 1.489

AL in progress

JUN 2017

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 32 / 46

slide-33
SLIDE 33

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

  • A. Adametz 2011 thesis B(fi → ı3ı0)

)) [%] (ex. K

τ

ν π 3

  • π

→

  • τ

B(

1 1.1 1.2 Adametz 2011 0.047 ± 0.010 ± 1.216 HFLAV Spring 2017 0.075 ± 1.029 HFLAV + Adametz 2011 0.034 ± 1.156

AL in progress

JUN 2017

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 33 / 46

slide-34
SLIDE 34

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

  • A. Adametz 2011 thesis B(fi → ı4ı0)

)) [%] η , (ex. K

τ

ν π 4

  • h

→

  • τ

B(

0.1 0.15 ALEPH 2005 0.051 ± 0.112 Adametz 2011 0.009 ± 0.007 ± 0.104 HFLAV Spring 2017 0.039 ± 0.110 HFLAV + Adametz 2011 0.009 ± 0.094

AL in progress

JUN 2017

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 34 / 46

slide-35
SLIDE 35

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

|Vus| fi → s inclusive, HFLAV 2017 + Adametz 2011 thesis

|

us

|V

0.22 0.225 CKM unitarity, PDG 2016 0.0009 ± 0.2258 s incl., HFLAV Spring 2017 → τ 0.0021 ± 0.2186 HFLAV + Adametz 2011 0.0019 ± 0.2192

AL in progress

JUN 2017 I using all Adametz 2011 results, no significant modification of |Vus| I Adametz 2011 B(fi → Kı0) increases |Vus| significantly I other Adametz 2011 results and correlations decrease |Vus| by a similar amount Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 35 / 46

slide-36
SLIDE 36

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

Using tau BRs predictions from kaon BRs

  • M. Antonelli et al., JHEP 10 (2013) 76

I |Vus| calculation using 3 tau BRs from kaons to replace the HFLAV averages I B(fi → K) = (0:713 ± 0:003)% I B(fi → Kı0) = (0:857 ± 0:030)% I B(fi → K0ı) = (0:471 ± 0:018)% I (the latter two uncertainties are 100% correlated)

B(fi → Kfi ) = m3

fi

2mKm2

—

Sfi

EW

SK

EW

„

1 − m2

K=m2 fi

1 − m2

—=m2 K

«2

fifi fiK Rfi=K

EM B(K—2)

B(fi → ¯ Kıfi ) = 2m5

fi

m5

K

Sfi

EW

SK

EW

Ifi

K

I‘

K

`

1 + ‹Kfi

EM + ˜

‹Kı

SU(2)

´2 `

1 + ‹K‘

EM + ‹Kı SU(2)

´2

fifi fiK B(K → ıe¯ e) [and similar formula for B(fi → Kı0)] phase space integrals, require tau spectral functions Ifi

K =

1 m2

fi

Z

m2 fi sKı

ds s√s

„

1 − s m2

fi

«2 »„

1 + 2s m2

fi

«

q3

Kı(s)| ¯

f+(s)|2 + 3∆2

Kı

4s qKı(s) | ¯ f0(s)|2

–

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 36 / 46

slide-37
SLIDE 37

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

Vus from HFLAV spring 2017 and kaon indirect BRs

I compute |Vus| with fi → s inclusive method using both tau and kaon data

(assuming Standard Model holds) (different from JHEP 10 (2013) 76, where tau BRs from kaon data replace tau BRs)

I in the following, tau BRs from kaons contribute to fit according to their uncertainties Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 37 / 46

slide-38
SLIDE 38

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

B(fi → K) HFLAV 2017 + indirect kaon BRs

) [%]

τ

ν

  • K

→

  • τ

B(

0.68 0.7 0.72 0.74 0.76 CLEO 1994 0.090 ± 0.070 ± 0.660 DELPHI 1994 0.180 ± 0.850 ALEPH 1999 0.029 ± 0.696 OPAL 2001 0.029 ± 0.027 ± 0.658 Antonelli 2013 0.003 ± 0.713 HFLAV Spring 2017 0.010 ± 0.696 HFLAV + kaon indirect BRs 0.003 ± 0.711

AL in progress

JUN 2017 Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 38 / 46

slide-39
SLIDE 39

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

B(fi → Kı0) HFLAV 2017 + indirect kaon BRs

) [%]

τ

ν π

  • K

→

  • τ

B(

0.4 0.45 0.5 0.55 CLEO 1994 0.070 ± 0.100 ± 0.510 ALEPH 1999 0.035 ± 0.444 OPAL 2004 0.023 ± 0.059 ± 0.471 BaBar 2007 0.018 ± 0.003 ± 0.416 Antonelli 2013 0.018 ± 0.471 HFLAV Spring 2017 0.015 ± 0.433 HFLAV + kaon indirect BRs 0.007 ± 0.455

AL in progress

JUN 2017 Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 39 / 46

slide-40
SLIDE 40

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

B(fi → K0ı) HFLAV 2017 + indirect kaon BRs

) [%]

τ

ν K

  • π

→

  • τ

B(

0.8 0.9 1 L3 1995 0.060 ± 0.150 ± 0.950 ALEPH 1999 0.056 ± 0.928 OPAL 2000 0.049 ± 0.068 ± 0.933 Belle 2014 0.015 ± 0.002 ± 0.832 Antonelli 2013 0.030 ± 0.857 HFLAV Spring 2017 0.014 ± 0.839 HFLAV + kaon indirect BRs 0.011 ± 0.832

AL in progress

JUN 2017 Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 40 / 46

slide-41
SLIDE 41

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

Vus from HFLAV spring 2017 and kaon indirect BRs

|

us

|V

0.22 0.225 CKM unitarity, PDG 2016 0.0009 ± 0.2258 s incl., HFLAV Spring 2017 → τ 0.0021 ± 0.2186 HFLAV + Adametz 2011 0.0019 ± 0.2192 HFLAV + indirect kaon BRs 0.0021 ± 0.2195

AL in progress

JUN 2017 I tau BRs from kaons cause small shift and no visible improvement in |Vus| precision Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 41 / 46

slide-42
SLIDE 42

Status and progress of the HFLAV-Tau group activities Further investigations on ˛

˛Vus ˛ ˛ from fi → s inclusive

|Vus| inclusive uncertainties budget (%)

after adding both Adametz 2011 and kaon indirect results

ı− ¯ K0ı0ı0fi (ex. K0) 0.3908 ¯ K0h−h−h+fi 0.3430 K−ı−ı+ı0fi (ex. K0; !; ”) 0.2422 ı− ¯ K0ı0fi 0.2178 K−!fi 0.1563 ı− ¯ K0fi 0.1501 K−ı−ı+fi (ex. K0; !) 0.1140 K−ı0fi 0.0881 K−3ı0fi (ex. K0; ”) 0.0703 K−fi 0.0473 K−2ı0fi (ex. K0) 0.0414 ı− ¯ K0”fi 0.0253 K−ı0”fi 0.0197 K−”fi 0.0136 K−ffifi (ffi → K+K−) 0.0136 K−ffifi (ffi → K0

SK0 L)

0.0095 K−2ı−2ı+fi (ex. K0) 0.0020 K−2ı−2ı+ı0fi (ex. K0) 0.0010 fi → non-strange 0.0853 Buniv

e

0.0045 theory 0.4724 Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 42 / 46

slide-43
SLIDE 43

Status and progress of the HFLAV-Tau group activities

HFLAV Tau LVF combinations

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 43 / 46

slide-44
SLIDE 44

Status and progress of the HFLAV-Tau group activities HFLAV Tau LVF combinations

HFLAV tau LFV limits

  • HFLAV

Spring 2017

10−8 10−6

e

−

γ µ

−

γ e

−

π µ

−

π e

−

K

S

µ

−

K

S

e

−

η µ

−

η e

−

η′(958) µ

−

η′(958) e

−

ρ µ

−

ρ e

−

ω µ

−

ω e

−

K

∗

(892) µ

−

K

∗

(892) e

−

K

∗

(892) µ

−

K

∗

(892) e

−

φ µ

−

φ e

−

f (980) µ

−

f (980) e

−

e

+

e

−

e

−

µ

+

µ

−

µ

−

e

+

µ

−

µ

−

e

+

e

−

e

−

µ

+

e

−

µ

−

µ

+

µ

−

e

−

π

+

π

−

e

+

π

−

π

−

µ

−

π

+

π

−

µ

+

π

−

π

−

e

−

π

+

K

−

e

−

K

+

π

−

e

+

π

−

K

−

e

−

K

S

K

S

e

−

K

+

K

−

e

+

K

−

K

−

µ

−

π

+

K

−

µ

−

K

+

π

−

µ

+

π

−

K

−

µ

−

K

S

K

S

µ

−

K

+

K

−

µ

+

K

−

K

−

π

−

Λ π

−

Λ pµ

−

µ

−

pµ

+

µ

−

  • ATLAS

BaBar Belle CLEO LHCb

90% CL upper limits on τ LFV decays

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 44 / 46

slide-45
SLIDE 45

Status and progress of the HFLAV-Tau group activities HFLAV Tau LVF combinations

HFLAV tau LFV limits combinations

  • HFLAV

Spring 2017

10−8 10−7

e

−

γ µ

−

γ e

−

π µ

−

π e

−

K

S

µ

−

K

S

e

−

η µ

−

η e

−

η′(958) µ

−

η′(958) e

−

ρ µ

−

ρ e

−

ω µ

−

ω e

−

K

∗

(892) µ

−

K

∗

(892) e

−

K

∗

(892) µ

−

K

∗

(892) e

−

φ µ

−

φ e

−

e

+

e

−

e

−

µ

+

µ

−

µ

−

e

+

µ

−

µ

−

e

+

e

−

e

−

µ

+

e

−

µ

−

µ

+

µ

−

  • BaBar

Belle LHCb HFLAV combination

90% CL upper limits on τ LFV decays

Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 45 / 46

slide-46
SLIDE 46

Status and progress of the HFLAV-Tau group activities Summary

Summary

I HFLAV report including tau averages submitted for publication in 2017 I HFLAV-Tau group provides PDG with BR fit results since 2016 I charged weak current lepton universality verified at better than 0.2% I |Vus| from fi → s inclusive shows discrepancy of ∼3 ff w.r.t. |Vus| from CKM unitarity I calculated |Vus| with the fi → s inclusive method using, in addition to HFLAV inputs, I Adametz thesis results I tau BRs computed from kaon BRs I in both cases, no significant change on |Vus| discrepancy Alberto Lusiani, SNS – PHIPSI 2017, 26-29 June 2017, Mainz, Germany 46 / 46