Minimal muon anomalous magnetic moment

Based on JHEP 02 (2015) 099 in collaboration with M. Bordone

Carla Biggio Universita` di Genova

INVISIBLES15 Workshop Madrid, 22-26 June 2015

The (g-2)μ anomaly

3.1

Brookhaven 2006

Jegerlehner, Nyffeler 2009 (e+e- annih.)

�

The (g-2)μ anomaly

3 ways out: - theoretical: bad estimation of hadronic contribution ➛ disfavoured - experimental: ➛ wait for new experiment - new physics !!!

Brookhaven 2006

Jegerlehner, Nyffeler 2009 (e+e- annih.)

Passera et al. 2008-09Fermilab J-PARC

3.1 �

The (g-2)μ anomaly

3 ways out: - theoretical: bad estimation of hadronic contribution ➛ disfavoured - experimental: ➛ wait for new experiment - new physics !!!

adopt this optimistic option :)

Brookhaven 2006

Jegerlehner, Nyffeler 2009 (e+e- annih.)

Passera et al. 2008-09Fermilab J-PARC

3.1 �

Explaining Δaμ with a single new particleAssumptions: 1. add only 1 particle to the SM

2. consider only fermions and scalars

Explaining Δaμ with a single new particle

In the SM (g-2) is a D=6 operator

At 1 loop, for example:

Assumptions: 1. add only 1 particle to the SM 2. consider only fermions and scalars

Explaining Δaμ with a single new particle

In the SM (g-2) is a D=6 operator

At 1 loop, for example:

Assumptions: 1. add only 1 particle to the SM 2. consider only fermions and scalars

Requirements: 1. Lorentz invariance 2. Gauge invariance 3. Renormalizability

New fermions

NR (1, 1, 0)�R (1, 3, 1)E4 (1, 1,�1)L4 (1, 2,�1/2)T (1, 3,�1)D (1, 2,�3/2)

typeI seesawtypeIII seesaw

4th generation.}

All vector-like: masses indep. of EWSB, no anomalies

New fermions

NR (1, 1, 0)�R (1, 3, 1)E4 (1, 1,�1)L4 (1, 2,�1/2)T (1, 3,�1)D (1, 2,�3/2)

typeI seesawtypeIII seesaw

4th generation.}

✘

✘CB 09

All vector-like: masses indep. of EWSB, no anomalies

New fermions

NR (1, 1, 0)�R (1, 3, 1)E4 (1, 1,�1)L4 (1, 2,�1/2)T (1, 3,�1)D (1, 2,�3/2)

typeI seesawtypeIII seesaw

4th generation.}

✘

✘✘

✘

CB 09, Freitas et al. 14

✘

All vector-like: masses indep. of EWSB, no anomalies

Freitas et al. 14

Freitas et al. 14

Only L4 gives a positive contribution but too small (EWPT)

✳

✳

New fermions

NR (1, 1, 0)�R (1, 3, 1)E4 (1, 1,�1)L4 (1, 2,�1/2)T (1, 3,�1)D (1, 2,�3/2)

typeI seesawtypeIII seesaw

4th generation.}

✘

✘✘

✘

CB 09, Freitas et al. 14

✘

All vector-like: masses indep. of EWSB, no anomalies

Freitas et al. 14

Only L4 gives a positive contribution but too small (EWPT)

✳

✳

Freitas et al. 14

?

The contribution of D ∼ (1,2,-3/2)

Q=1

Q=2

SM

CB, Bordone 14

The contribution of D ∼ (1,2,-3/2)

Q=1

Q=2

The new contribution is negative it cannot explain the discrepancy

SM

CB, Bordone 14

New fermions

NR (1, 1, 0)�R (1, 3, 1)E4 (1, 1,�1)L4 (1, 2,�1/2)T (1, 3,�1)D (1, 2,�3/2)

typeI seesawtypeIII seesaw

4th generation.}

✘

✘✘

✘

CB 09, Freitas et al. 14

✘

All vector-like: masses indep. of EWSB, no anomalies

Freitas et al. 14 CB, Bordone 14

Freitas et al. 14

✘ CB, Bordone 14

It’s not possible to explain the discrepancy adding to the SM a single fermion

New scalars

type II seesaw

S1 (1, 1, 1)S2 (1, 1, 2)H2 (1, 2, 1/2)� (1, 3, 1)

T 1/3c (3, 3,�1/3)

S1/3c (3, 1,�1/3)

S4/3c (3, 1,�4/3)

D7/6c (3, 2, 7/6)

D1/6c (3, 2, 1/6)

II Higgs doublet

leptoquarks

New scalars

type II seesaw

S1 (1, 1, 1)S2 (1, 1, 2)H2 (1, 2, 1/2)� (1, 3, 1)

T 1/3c (3, 3,�1/3)

S1/3c (3, 1,�1/3)

S4/3c (3, 1,�4/3)

D7/6c (3, 2, 7/6)

D1/6c (3, 2, 1/6)

II Higgs doublet

✘

✘

✘

Coaraza Perez et al. 95

Gunion et al. 89

(from S1 and S2 results)

leptoquarks

New scalars

type II seesaw

S1 (1, 1, 1)S2 (1, 1, 2)H2 (1, 2, 1/2)� (1, 3, 1)

T 1/3c (3, 3,�1/3)

S1/3c (3, 1,�1/3)

S4/3c (3, 1,�4/3)

D7/6c (3, 2, 7/6)

D1/6c (3, 2, 1/6)

II Higgs doublet

✘

✘

✘

✘

✘

✘

✔

✔

Chakraverty et al. 01 Cheung 01

Coaraza Perez et al. 95

Gunion et al. 89

(from S1 and S2 results)

leptoquarks

New scalars

type II seesaw

S1 (1, 1, 1)S2 (1, 1, 2)H2 (1, 2, 1/2)� (1, 3, 1)

T 1/3c (3, 3,�1/3)

S1/3c (3, 1,�1/3)

S4/3c (3, 1,�4/3)

D7/6c (3, 2, 7/6)

D1/6c (3, 2, 1/6)

II Higgs doublet

✘

✘

✘

✘

✘

✘

✔

✔

Chakraverty et al. 01 Cheung 01

Coaraza Perez et al. 95

Gunion et al. 89

(from S1 and S2 results)

leptoquarks

Only these because they have both L and R couplings ➢ enhancement with top (charm) mass

New scalars

type II seesaw

S1 (1, 1, 1)S2 (1, 1, 2)H2 (1, 2, 1/2)� (1, 3, 1)

T 1/3c (3, 3,�1/3)

S1/3c (3, 1,�1/3)

S4/3c (3, 1,�4/3)

D7/6c (3, 2, 7/6)

D1/6c (3, 2, 1/6)

II Higgs doublet

✘

✘

✘

✘

✘

✘

✔

✔

✔

Chakraverty et al. 01 Cheung 01

Coaraza Perez et al. 95

Gunion et al. 89

Broggio et al. 14

In a particular 2HDM if lighter than 200 GeV

(from S1 and S2 results)

leptoquarks

Only these because they have both L and R couplings ➢ enhancement with top (charm) mass

The bR of the Higgsinoless MSSM∼

Riva, CB, Pomarol 12

It’s a SUSY model without R-parity (with U(1)R) where there are NO chiral Higgs superfields: the Higgs is identified with a sneutrino

The bR of the Higgsinoless MSSM∼

Riva, CB, Pomarol 12

It’s a SUSY model without R-parity (with U(1)R) where there are NO chiral Higgs superfields: the Higgs is identified with a sneutrino

W � YdL�QD L� = (�̃� � H, ��)

The bR of the Higgsinoless MSSM∼

Riva, CB, Pomarol 12

It’s a SUSY model without R-parity (with U(1)R) where there are NO chiral Higgs superfields: the Higgs is identified with a sneutrino

W � YdL�QD L� = (�̃� � H, ��)

Ydh0bLbR + Ydl�tLb̃R + ...

The bR of the Higgsinoless MSSM∼

Riva, CB, Pomarol 12

It’s a SUSY model without R-parity (with U(1)R) where there are NO chiral Higgs superfields: the Higgs is identified with a sneutrino

W � YdL�QD L� = (�̃� � H, ��)

Ydh0bLbR + Ydl�tLb̃R + ...

l� � µIn our case , the bR coupling is fixed to be Yb

aLQµ � v2Y 2

b

M2LQ

we have a prediction for MLQ

Mb̃R� 500GeV

The bR of the Higgsinoless MSSM∼

CB Bordone 14

In the Higgsinoless MSSM we can explain the (g-2) anomaly with a sbottom of mass Mb̃R

� 500 GeV

The bR of the Higgsinoless MSSM∼

CB Bordone 14

In the Higgsinoless MSSM we can explain the (g-2) anomaly with a sbottom of mass

Which are the current bounds?

Mb̃R� 500 GeV

The bR of the Higgsinoless MSSM∼

CB Bordone 14

Bounds from decay into bv: Br=1 M>620 GeV Br=0.6 M>520 GeV

ATLAS 13

In the Higgsinoless MSSM we can explain the (g-2) anomaly with a sbottom of mass

Which are the current bounds?

Mb̃R� 500 GeV

The bR of the Higgsinoless MSSM∼

CB Bordone 14

Bounds from decay into bv: Br=1 M>620 GeV Br=0.6 M>520 GeV

ATLAS 13

In the Higgsinoless MSSM we can explain the (g-2) anomaly with a sbottom of mass

Which are the current bounds?

In our model: b̃R � bL�L

tLlL(bRG̃)

same BR

Mb̃R� 500 GeV

This possibility is viable, to confirm/exclude it look for final states with top and charged leptons!!!

ConclusionsWe have considered single particle extensions of the SM (scalar & fermion)

A single new fermion cannot explain the (g-2)μ anomaly

Only 3 scalars -2 leptoquarks and a second Higgs doublet- can do it

The bR of the Higgsinoless MSSM could solve the (g-2)μ puzzle and we have a prediction for its mass:

Most of these solutions are going to be tested @ LHC13

Wait for new LHC run and new (g-2)μ experiment!

Mb̃R� 500 GeV

Muchas gracias

!

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