Leptophilic new physics at the LHC Mikael Chala , F. del guila, Y. - - PowerPoint PPT Presentation

Mikael Chala, VI CPAN Days, Sevilla

Mikael Chala,

• F. del Águila, Y. Yamamoto & J. Santiago

(Universidad de Granada) Based on JHEP 1403 (2014) 027 & CAFPE-183/14

Leptophilic new physics at the LHC

Outline

The properties of leptophilic physics Current and future constraints The limit of large masses The nature of LNV scalars Current and future constraints Conclusions

Leptophilic Z' LNV scalar interactions

Mikael Chala, VI CPAN Days, Sevilla

Structure of leptophilic physics

Scalar 1

non-renormalizable lepton interactions

Vector 1

renormalizable lepton interactions

lll & llll signals as other new physics (to be discussed later) Mikael Chala, VI CPAN Days, Sevilla

The renormalizable lagrangian of a leptophilic Z'

Mikael Chala, VI CPAN Days, Sevilla quantum number

1 1 -1 -1

anomaly free, Foot et al '94

Mikael Chala, VI CPAN Days, Sevilla Mikael Chala, VI CPAN Days, Sevilla

LEP and LFV constraints

Precision measurements at Z pole & above Z pole

Carena et al '04 Sindrum & PSI Bell Collab.

Mikael Chala, VI CPAN Days, Sevilla Mikael Chala, VI CPAN Days, Sevilla

LEP and LFV constraints

Parameterize the lagrangian (up to taus) by means of and

Cross section at the LHC given (to very good accuracy) by

Mikael Chala, VI CPAN Days, Sevilla

Test these interactions in lll and llll final states

Order fb at both LHC and ILC Z-Z' mixing effects

• n Drell-Yan are

model dependent

Aguila, Coughlan & Quirós '88, Holdom, '91, Aguila, Masip & Perez-Victoria, '95

LHC reach

Mikael Chala, VI CPAN Days, Sevilla is also shown in the pictures, while

g-2 is only relevant for small masses [Ma, Roy & Roy, '02]

Mikael Chala, VI CPAN Days, Sevilla

ILC reach (taus are also considered)

Both Z' decays are included in any case, but a priori they can be splitted

Mikael Chala, VI CPAN Days, Sevilla

Test these interactions in lll and llll final states

Order fb at both LHC and ILC Z-Z' mixing effects

• n Drell-Yan are

model dependent

Aguila, Coughlan & Quirós '88, Holdom, '91, Aguila, Masip & Perez-Victoria, '95

Mikael Chala, VI CPAN Days, Sevilla

The limit of large Z' mass

Can be also induced by

Experiment scale

Different doubly-charged scalar at a lower scale can mix with

LNV extensions of the SM can accommodate neutrino Majorana masses Only three scalar fields at the renormalizable level

Mikael Chala, VI CPAN Days, Sevilla

After integrating out scale, higher multiplets ( ) couple to same-sign leptons via Yukawa-like interactions

and suppressed by powers of Off-diagonal couplings suppressed by LFV bounds Mikael Chala, VI CPAN Days, Sevilla

What is the phenomenology of these scalars? VS What current analyses assume (see-saw II)?

ATLAS

E u r . P h y s . J

C72-2244

CMS

E u r . P h y s . J

C72-2189

Mikael Chala, VI CPAN Days, Sevilla

Using current CMS three- and four-lepton analyses, set bounds on LNV processes mediated by doubly-charged scalars Mikael Chala, VI CPAN Days, Sevilla

Using current CMS three- and four-lepton analyses, set bounds on LNV processes mediated by doubly-charged scalars Mikael Chala, VI CPAN Days, Sevilla

Conclusions

Mikael Chala, VI CPAN Days, Sevilla

There are no signals of new physics at the LHC. So, either new physics is at a larger scale, or it is somehow elusive. Concerning leptophilic physics, LHC and ILC will be complementary, although no much room for ILC discovery. Higher scales can not be successfully tested in both colliders, but LNV could be efficiently searched for.

Mikael Chala, VI CPAN Days, Sevilla

Thank you!

Backup

Mikael Chala, VI CPAN Days, Sevilla

Can we discriminate among the different multiplets? LNV can be very difficult to be established at the LHC But doubly-charged scalars can be still present Discrimination is possible if two-body decays dominate

Measure the neutral cross section using four-lepton events

(and observe signals

• f a charged channel)

Mikael Chala, VI CPAN Days, Sevilla

How well can we discriminate among the different multiplets?

14 TeV, L = 100, 300, 3000/fb

• Only light

leptons

• Light leptons

and taus

• Light leptons

and Ws

• Light leptons

taus and Ws Mikael Chala, VI CPAN Days, Sevilla