Prog. Part. Nucl. Phys. 75 (2014) 41 τ Physics. Antonio Pich. IFIC, Univ. Valencia CSIC

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1 Prog. Part. Nucl. Phys. 75 (014) 41 Physics Antonio Pich IFIC, Univ. Valencia CSIC MASS 018: Origin of Mass at the High Energy and Intensity Frontier CP 3 -Origins, SDU, Odense, Denmark, 8 May 1 June 018

2 TAU PHYSICS Decay QCD W ν e, µ ν, ν e µ W ν d θ u Hadrons Production New Physics e γ,z H 0 H e ν b W c ν Neutrino Physics A. Pich Physics

3 LEPTONIC DECAYS W ν e, µ ν, ν e µ G m Γ( ν lνl ) = ( / ) +δ 19π 5 F f m 3 l m RC 3 4 f( x) = 1 8x+ 8x x 1x log x ( 1 ) (elle), m (esiii) e µ = = ± ± ( ) 10 s ( ) e exp µ / = ± Non-F: ± aar 10: ± ( ) univ = ± e % A. Pich Physics 3

4 Charged Current Universality g µ / ge µ e π µ π e K µ K e K πµ K πe W µ W e g / g µ µ µ g / ge ± Γ Γ e µ Γ π π µ Γ K K µ ± ± ± W W e 1.031± W W µ ± A. Pich Physics 4

5 Charged Current Universality g µ / ge µ e π µ π e K µ K e K πµ K πe W µ W e g anomaly cannot be accommodated with EFT Filipuzzi, Gonzalez-Alonso, Portoles, g / g µ µ µ g / ge ± Γ Γ e µ Γ π π µ Γ K K µ ± ± ± W W e 1.031± W W µ ± σ.6 σ A. Pich Physics 5

6 Lorentz Structure: Effective Hamiltonian: Normalization: High-precision data needed! A. Pich Physics 6

7 HADRONIC TAU DECAY ν Hadrons W d θ d = V d + θ V s ud us u Only lepton massive enough to decay into hadrons R ( ν Hadrons) Γ( ν e νe ) Γ + N C 1 e µ ; R = = ± e R ( ν + Hadrons) 1 r = = ± ; R univ = = ± univ e e A. Pich Physics 7

8 e γ γ σ Ιm e + q q e e + + σ ( ee had) + + σ ( ee µµ ) = 1π Im Π ( s) em iqx ( ) Π ( q) i dxe 0 TJ [ ( xj ) (0)] 0 = g q+ qq Π ( q) µν 4 µ ν µν µ ν em em em em W W Γ ν + had Ιm d,s u ν ν m ds s s (1) (0) 1π 1 1 Im ( ) Im ( ) 0 Γ( ν + had) R = + Π s + Π s Γ( ν e νe) m m m ( J) ( J) ( J) ( J) ( J) ud ud, V ud, A us us, V us, A Π () s V Π () s +Π () s + V Π () s +Π () s iqx ( ) Π ( ) e 0 [ ( ) (0) ] 0 = + Π ( ) + Π ( ) µν 4 µ ν µν µ ν (1) µ ν (0) ij, J q i dx TJij xjij g q qq ij, J q qq ij, J q A. Pich Physics 8

9 SPECTRAL FUNCTIONS Davier et al, v() s = π Im Π () s (0+ 1) 1 ud, V a() s = π Im Π () s (0+ 1) 1 ud, A etter data needed A. Pich Physics 9

10 QCD Prediction of R raaten-narison-pich 9 Γ( ν + had) 1 (1) (0) R = 1 π dx (1 x) (1 + x) Im Π ( xm) + Im ( xm) ( ν e ν ) 0 Π Γ Im (s) e x sm t m R = + Π Π 6 (1 ) ( (0+ 1) ( ) (0) ( πi dx x 1 x) xm x xm ) 1 x = Re (s) ( J ) ( J ) CD s OD () s D / D= n ( s) Π = (, µ ) ( µ ) OPE R = N + δ + δ = R + + S ( ) EW 1 P NP, R, R, C V A S S = (3) ; δ = ± 03 1 EW NP Marciano-Sirlin, raaten-li, Erler Fitted from data (Davier et al) δ α π 3 4 P = a a + 6 a + 17 a % ; a ( m ) / s (aikov-chetyrkin-kühn A. Pich Physics 10

11 Perturbative (m q =0) d (0+ 1) 1 α ( ) () K s s s Π s = ds n π 4π n= 0 n K = K = 1, K = , K = , K = (aikov-chetyrkin-kühn δ Le Diberder- Pich 9 P n= 1 ( n) 3 4 = K A ( α ) = a a + 6 a + 17 a + n s n ( n) 1 dx 3 4 αs( s) n αs a a 1 x s m i α π + = + = x π A ( ) (1 x x x ) ; ( ) / π Power Corrections raaten-narison-pich 9 1 (0+1) n n ΠOPE () s 4 n π ( s) n C O π C4 O4 0 αsg µν Gµν 0 3 δ 1 π i 3 n n NP dx (1 3x + x ) 3 x = 1 n = 6 8 n C O ( xm ) C O C 6 V A Suppressed by m [additional chiral suppression in C6 O + 6 ] m m O A. Pich Physics 11

12 Spectral Function Distribution Moments: k l kl s s s dr 0 ( 0) R s ds s m ds Sensitivity to power corrections (k,l) The non-perturbative contribution to R can be obtained from the invariant-mass distribution of the final hadrons δ NP = ± Davier et al. (ALEPH data) A. Pich Physics 1

13 New Analysis of ALEPH Data Rodríguez-Sánchez, Pich A. Pich Physics 13

14 Present Status Rodríguez-Sánchez, Pich α = ± ( ) s m α = ± ( ) s M Z s M Z Zwidth α ( ) = ± Very precise test of Asymptotic Freedom α s Z ( MZ) α ( MZ) = s ± ± Z A. Pich Physics 14

15 Chiral Sum Rules Π( s) ΠVV ( s) -ΠAA ( s) Pure non-perturbative quantity χpt (s 0): OPE O6 O8 lim s Π ( s) = 0 Π ( s) = + s 3 4 s s F 1 5 () 8 10( ) r s r s L ln ( ) s m C m s p m F Statistical analysis: González-Pich-Rodríguez, χpt Im (s) OPE m Re (s) Non-pinched & pinched weights A. Pich Physics 15

16 A. Pich Physics 16

17 V us Determination Gámiz-Jamin-Pich-Prades-Schwab V us = R 00, V+ A V ud R 00, S δ R 00,th δ R kl m ( ) 4 s m kl m ( αs) 00 δ R,th (37) (3) = 0.40 (3) J=0 m s ( GeV) = 94 (6) MeV R R V 00, S 00, V+ A ud = (7) = (7) = (1) V = ± ± us exp th K l3 : Vus = 0.31± [ f (0) = ± ] A. Pich Physics 17

18 V us Determination Gámiz-Jamin-Pich-Prades-Schwab V us = R 00, V+ A V ud R 00, S δ R 00,th δ R kl m ( ) 4 s m kl m ( αs) 00 δ R,th (37) (3) = 0.40 (3) J=0 m s ( GeV) = 94 (6) MeV R R V 00, S 00, V+ A ud = (7) = (7) = (1) V = ± ± us exp th K data 00 R =, S (34) V = 0.08 ± ± us exp th K l3 : Vus = 0.31± [ f (0) = ± ] The could give the most precise V us determination A. Pich Physics 18

19 Use information from K decays Antonelli-Cirigliano-Lusiani-Passemar (0.713 ± 0.003)% (0.471 ± 0.018)% HFLAV 017: (.9087 ± 0.048) 10 - (0.857 ± 0.030)% (.967 ± 0.060)% Larger R S Larger V us A. Pich Physics 19

20 Invariant Mass Spectra Gómez Dumm - Roig ν π π 0 aar elle data Jamin-Pich-Portolés ν π K S elle data Useful tests of QCD Dynamics Form Factors Non-perturbative parameters Resonance Chiral Theory (RχT) A. Pich Physics 0

21 90% CL Upper Limits on LFV Decays MEG: r (µ e γ) < Kicking Out Models J. Hisano A. Pich Physics 1

22 Flavour-Violating Higgs Couplings ( H µ ) r < 0.5% ( 95% CL) A. Pich Physics

23 A CP Asymmetry + + ( π KSν ) ( π KSν ) + + ( π KSν ) ( π KSν ) Γ Γ = ± ± Γ +Γ 3 ( ) 10 aar 11 0p t p n SM 3 A K S = igi-sanda, Grossman-Nir.8 σ discrepancy t t elle does not see any asymmetry at the 10 - level CP A cos cos t t i b y cosb cosy i i bins ( i) of W Q b K S direction in hadronic rest frame y t direction aar signal incompatible with other sets of flavour data Cirigliano-Crivellin-Hoferichter, A. Pich Physics 3

24 006 ν Anomaly b _ u W _ ν elle 006: (hadronic tag) ν = r( ) (1.7 ) 10 Large V ub Tension in CKM fit Confirmed by aar (008, 010, 013) elle 013: (hadronic tag) ν = ± 0.5 r( ) ( ) 10 Current status: CKM agreement. Tension between elle and aar A. Pich Physics 4

25 Flavour Anomaly 4 σ discrepancy RD (*) ( ) (*) r ( D ν ) (*) r ( D ν ) b W cu, 68% CL 95% CL ν elle, igi-gambino-schacht A. Pich Physics 5

26 b H cu, ν A. Pich Physics 6

27 LHCb, σ above SM prediction b W cu, ν ( J / ψ ) SM Yu et al, Ivanov et al, Kiselev, Hernández et al A. Pich Physics 7

28 Capdevila et al, ) New physics only contributes to the SM operator µ [ cγ Pb][ γ Pν ] L µ L ) At higher scales, it originates from (avoids b sνν constraints) [ Q γ Q ][ L γ L ] + [ Q γ σ Q ][ L γ σ L ] [( c γ b )( γ ν ) + ( s γ b )( γ )] µ µ I I µ µ 3 3 µ µ 3 L µ L L L L µ L L L Large r(b s + ) See also: Alonso et al, Crivellin et al, A. Pich Physics 8

29 LHC Excellent signature to probe New Physics Difficult to identify light objects (Z,W ± ) with only Jets QCD Jets orders of magnitude larger Must rely on leptons LHC produces high-momenta s Tightly collimated decay products (mini-jet like) Momentum reconstruction possible Low multiplicity. Good tagging efficiency Heaviest lepton coupling to the Higgs (4 th H r) Polarization information A. Pich Physics 9

30 SUMMARY Many interesting topics Tests of QCD and the Electroweak Theory Looking for Signals of New Phenomena Superb Tool for New Physics Searches Current anomalies: etter data samples needed Lots of data will be elle-ii & LHC Improving systematics brings a great reward A. Pich Physics 30

31 ackup MASS 018: Origin of Mass at the High Energy and Intensity Frontier CP 3 -Origins, SDU, Odense, Denmark, 8 May 1 June 018

32 Only Lepton Massive Enough to Decay into Hadrons ν H probes the hadronic V-A current W ν d θ Hadrons µ θ γ H d (1 γ ) u 0 5 u e + e H 0 probes the hadronic electromagnetic current e e + γ Hadrons γ µ 0 H Qq q q q 0 Isospin: Γ( ν V ) 3cos θ Γ( ν e ν ) πα 1 C I = 1 = S EW dx (1 x) (1 x) x σ + 0 xm + 0 ee V e ( ) A. Pich Physics 3

33 LORENTZ STRUCTURE 95% CL Stahl, PDG16 t en n e t 90% CL Fetscher-Gerber, PDG16 m en n e m t mn n m t t pn t t rn t t a1 n t A. Pich Physics 33

34 R suitable for a precise α s determination Im (s) m R = + Π Π (0+ 1) (0) 6 πi dx (1 x) ( 1 x) ( xm ) x ( xm ) 1 x = Re (s) ( J ) ( J ) CD s OD () s D / D= n ( s) Π = (, µ ) ( µ ) OPE m large enough to safely use the OPE OPE only valid away from the real axis: (1-x) pinched at s = m m u,d = 0 s Π (0) (s) = 0 R = π + Π 3 (0+ 1) 6 i dx (1 3x x ) ( xm ) 1 x = δ NP 1/ m 6 Strong suppression of non-perturbative effects D=6 OPE contributions have opposite sign for V & A. Cancellation δ NP can be determined from data A. Pich Physics 34

35 Decay Averages PDG 014: 19 of the -factory branching fraction measurements are smaller than the non--factory values. The average normalized difference between the sets of measurements is (-1.41 elle / aar) Missing modes? Factories: High statistics. ut Err syst > Err stat A. Pich Physics 35

36 µ Anomalous Z. Zhang Magnetic Moment exp a µ = ( ± 6.3) 10 th a µ NL-E = ± QED Aoyama-Hayakawa-Kinoshita-Nio ± 0.1 EW Gnendiger et al, Czarnecki et al, Knecht et al ± 5.3 hvp (703.0 ± 4.4), (69.3 ± 4.) e + e Davier et al, Hagiwara et al, Jegerlehner-Nyffeler 8.6 ± 0.1 hvp NLO+NNLO Kurz et al, Hagiwara et al, Krause ±.6 light-by-light de Rafael-Prades-Vainshtein, Knecht et al, Melnikov-Vainshtein, Nyffeler, ijnens et al, Hayakawa et al, Goecke et al, Roig et al, Masjuan-Vanderhaeghen a -10 = ± 5.9 ( ± 5.1), ( ± 4.9) e + e th a =.6 σ.1 σ 3.4 σ exp µ µ A. Pich Physics 36

37 Anomalous Magnetic Moment Difficult to measure! exp a = ( ± 0.017) DELPHI New Phys < < González-Springer, Santamaria, Vidal 00 (LEP/SLD data) a Eidelman, Passera th a 10 8 = ± QED ± 0.5 EW ± 3.7 hvp ± 0. hvp NLO + 5 ± 3 light-by-light = ± 5 Enhanced sensitivity to new physics: m m 83 t m Essentially unknown May be accessible at Fs through radiative leptonic decays (Fael et al) A. Pich Physics 37