Lepton number violation in non-standard Higgs sectors Mikael Chala - - PowerPoint PPT Presentation

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lepton number violation in non standard higgs sectors
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Lepton number violation in non-standard Higgs sectors Mikael Chala - - PowerPoint PPT Presentation

May 24, 2023 203 likes •620 views

Lepton number violation in non-standard Higgs sectors Mikael Chala (DESY) & Francisco del guila (UGR) Based on JHEP 1403 (2014) 027, Phys.Lett. B725 (2013) 310 Mikael Chala, DISCRETE 2014, London The discovery of the Higgs boson shows a

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Mikael Chala, DISCRETE 2014, London

Mikael Chala (DESY) & Francisco del Águila (UGR)

Based on JHEP 1403 (2014) 027, Phys.Lett. B725 (2013) 310

Lepton number violation in non-standard Higgs sectors

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The discovery of the Higgs boson shows a very SM-like theory

Alex Pomarol, CPAN 2014

Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Many orders of magnitude

  • f unknown physics?

Model

Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Model Hierarchy problem

Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Model Hierarchy problem D a r k M a t t e r

Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Model Hierarchy problem D a r k M a t t e r

G r a v i t y

Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Model Hierarchy problem D a r k M a t t e r

G r a v i t y

Neutrino masses

Mikael Chala, DISCRETE 2014, London

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About Lepton Number Violation

Accidental from gauge symmetry Majorana neutrinos...

LNV !

Where to look for LN violation? decay Testable at the LHC?

Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Model

Natural assumption Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Model

Natural assumption Mikael Chala, DISCRETE 2014, London

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Planck scale

TeV scale EW scale

Model

Natural assumption

See for instance del Águila et al, 1204.5986; del Águila et al, 1111.6960

Mikael Chala, DISCRETE 2014, London

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Outline

Distinguishing LNV scalars at the LHC RUN2

Can LNV scalar interactions be observed at the LHC? A generic approach to LNV scalars

Mikael Chala, DISCRETE 2014, London

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

Mikael Chala, DISCRETE 2014, London

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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, DISCRETE 2014, London

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

Mikael Chala, DISCRETE 2014, London

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

and suppressed by powers of Mikael Chala, DISCRETE 2014, London

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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, DISCRETE 2014, London

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Using current CMS three- and four-lepton analyses, set bounds on LNV processes mediated by doubly-charged scalars Mikael Chala, DISCRETE 2014, London

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Mikael Chala, DISCRETE 2014, London

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Mikael Chala, DISCRETE 2014, London

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Mikael Chala, DISCRETE 2014, London

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Mikael Chala, DISCRETE 2014, London

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Using current CMS three- and four-lepton analyses, set bounds on LNV processes mediated by doubly-charged scalars Mikael Chala, DISCRETE 2014, London

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Using current CMS three- and four-lepton analyses, set bounds on LNV processes mediated by doubly-charged scalars Mikael Chala, DISCRETE 2014, London

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  • F. del Águila and M.C., 1311.1510

(see also King, Merle and Panizzi, arXiv:1406.4137)

E f f i c i e n c i e s i n %

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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

arXiv:1305.3904

Mikael Chala, DISCRETE 2014, London

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Mikael Chala, DISCRETE 2014, London

Distinguishing the different four-lepton channels

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Mikael Chala, DISCRETE 2014, London

Distinguishing the different four-lepton channels

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Mikael Chala, DISCRETE 2014, London

Distinguishing the different four-lepton channels

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Mikael Chala, DISCRETE 2014, London

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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

Águila, MC, Santamaría, Wudka, '13

Mikael Chala, DISCRETE 2014, London

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Doublet case Singlet case

Can be a background of

Mikael Chala, DISCRETE 2014, London

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Charged signals VS neutral current backgrounds

Cut here

mainly signal

Mikael Chala, DISCRETE 2014, London

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Conclusions

Mikael Chala, DISCRETE 2014, London

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The SM describes nature to a very good accuracy, although there are still open questions: neutrino masses LNV scalar interactions can be very difficult to be proved at the LHC For the first time, bounds on LNV scalar interactions, and many other channels

Thank you!

Even if no LNV, doubly-charged scalars can be distinguished in a large run of LHC

Mikael Chala, DISCRETE 2014, London

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What do we know on neutrino masses? Quantum numbers

Singlet!

Neutrinos can be Majorana

Other fermions are charged, so they can not be self-conjugated

Neutrino oscillations can not test the Majorana character

Mikael Chala, DISCRETE 2014, London

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Mikael Chala, DISCRETE 2014, London

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Using current CMS three- and four-lepton analyses, bound non-LNV processes mediated by doubly-charged scalars Mikael Chala, DISCRETE 2014, London

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Mikael Chala, DISCRETE 2014, London