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Title: The eejj excess signal at the LHC and constraints on leptogenesis

Abstract

We review the non-supersymmetric (Extended) Left-Right Symmetric Models (LRSM) and low energy E{sub 6}-based models to investigate if they can explain both the recently detected excess eejj signal at CMS and leptogenesis. The eejj excess can be explained from the decay of the right-handed gauge bosons (W{sub R}) with mass ∼ TeV in certain variants of the LRSM (with g{sub L}≠g{sub R}). However such scenarios can not accommodate high-scale leptogenesis. Other attempts have been made to explain leptogenesis while keeping the W{sub R} mass almost within the reach of the LHC by considering the resonant leptogenesis scenario in the context of the LRSM for relatively large Yukawa couplings. However, certain lepton number violating scattering processes involving the right-handed Higgs triplet and the right-handed neutrinos can stay in equilibrium till the electroweak phase transition and can washout the lepton asymmetry generated in the resonant leptogenesis scenario for mass range of W{sub R} as indicated by the CMS excess signal. Thus in such a scenario one needs to invoke post-sphaleron baryogenesis to explain the observed baryon asymmetry of the universe. Next, we consider three effective low energy subgroups of the superstring inspired E{sub 6} model having a number of additional exotic fermionsmore » which provides a rich phenomenology to be explored. We however find that these three effective low energy subgroups of E{sub 6} too cannot explain both the eejj excess signal and leptogenesis simultaneously.« less

Authors:
 [1];  [1];  [2]; ;  [1]
  1. Physical Research Laboratory,Navrangpura, Ahmedabad 380 009 (India)
  2. (India)
Publication Date:
Sponsoring Org.:
SCOAP3, CERN, Geneva (Switzerland)
OSTI Identifier:
22458375
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 09; Other Information: PUBLISHER-ID: JCAP09(2015)035; OAI: oai:repo.scoap3.org:11780; Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; BARYONS; CERN LHC; CMS DETECTOR; HIGGS BOSONS; LEPTON NUMBER; NEUTRINOS; PARTICLE PRODUCTION; PHASE TRANSFORMATIONS; SCATTERING; SIGNALS; SUPERSTRING MODELS; SUPERSYMMETRY; TEV RANGE; TRIPLETS; UNIVERSE; YUKAWA POTENTIAL

Citation Formats

Dhuria, Mansi, Hati, Chandan, Indian Institute of Technology Gandhinagar,Chandkheda, Ahmedabad 382 424, Rangarajan, Raghavan, and Sarkar, Utpal. The eejj excess signal at the LHC and constraints on leptogenesis. United States: N. p., 2015. Web. doi:10.1088/1475-7516/2015/09/035.
Dhuria, Mansi, Hati, Chandan, Indian Institute of Technology Gandhinagar,Chandkheda, Ahmedabad 382 424, Rangarajan, Raghavan, & Sarkar, Utpal. The eejj excess signal at the LHC and constraints on leptogenesis. United States. doi:10.1088/1475-7516/2015/09/035.
Dhuria, Mansi, Hati, Chandan, Indian Institute of Technology Gandhinagar,Chandkheda, Ahmedabad 382 424, Rangarajan, Raghavan, and Sarkar, Utpal. 2015. "The eejj excess signal at the LHC and constraints on leptogenesis". United States. doi:10.1088/1475-7516/2015/09/035.
@article{osti_22458375,
title = {The eejj excess signal at the LHC and constraints on leptogenesis},
author = {Dhuria, Mansi and Hati, Chandan and Indian Institute of Technology Gandhinagar,Chandkheda, Ahmedabad 382 424 and Rangarajan, Raghavan and Sarkar, Utpal},
abstractNote = {We review the non-supersymmetric (Extended) Left-Right Symmetric Models (LRSM) and low energy E{sub 6}-based models to investigate if they can explain both the recently detected excess eejj signal at CMS and leptogenesis. The eejj excess can be explained from the decay of the right-handed gauge bosons (W{sub R}) with mass ∼ TeV in certain variants of the LRSM (with g{sub L}≠g{sub R}). However such scenarios can not accommodate high-scale leptogenesis. Other attempts have been made to explain leptogenesis while keeping the W{sub R} mass almost within the reach of the LHC by considering the resonant leptogenesis scenario in the context of the LRSM for relatively large Yukawa couplings. However, certain lepton number violating scattering processes involving the right-handed Higgs triplet and the right-handed neutrinos can stay in equilibrium till the electroweak phase transition and can washout the lepton asymmetry generated in the resonant leptogenesis scenario for mass range of W{sub R} as indicated by the CMS excess signal. Thus in such a scenario one needs to invoke post-sphaleron baryogenesis to explain the observed baryon asymmetry of the universe. Next, we consider three effective low energy subgroups of the superstring inspired E{sub 6} model having a number of additional exotic fermions which provides a rich phenomenology to be explored. We however find that these three effective low energy subgroups of E{sub 6} too cannot explain both the eejj excess signal and leptogenesis simultaneously.},
doi = {10.1088/1475-7516/2015/09/035},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 09,
volume = 2015,
place = {United States},
year = 2015,
month = 9
}
  • We review the non-supersymmetric (Extended) Left-Right Symmetric Models (LRSM) and low energy E{sub 6}-based models to investigate if they can explain both the recently detected excess eejj signal at CMS and leptogenesis. The eejj excess can be explained from the decay of the right-handed gauge bosons (W{sub R}) with mass ∼ TeV in certain variants of the LRSM (with g{sub L}≠ g{sub R}). However such scenarios can not accommodate high-scale leptogenesis. Other attempts have been made to explain leptogenesis while keeping the W{sub R} mass almost within the reach of the LHC by considering the resonant leptogenesis scenario in the contextmore » of the LRSM for relatively large Yukawa couplings. However, certain lepton number violating scattering processes involving the right-handed Higgs triplet and the right-handed neutrinos can stay in equilibrium till the electroweak phase transition and can washout the lepton asymmetry generated in the resonant leptogenesis scenario for mass range of W{sub R} as indicated by the CMS excess signal. Thus in such a scenario one needs to invoke post-sphaleron baryogenesis to explain the observed baryon asymmetry of the universe. Next, we consider three effective low energy subgroups of the superstring inspired E{sub 6} model having a number of additional exotic fermions which provides a rich phenomenology to be explored. We however find that these three effective low energy subgroups of E{sub 6} too cannot explain both the eejj excess signal and leptogenesis simultaneously.« less
  • We study the constraints on a minimal supersymmetric seesaw model imposed by neutrino data, charged lepton flavor violation, thermal leptogenesis, and perturbativity. We show that it is possible to constrain the three heavy Majorana neutrino masses as well as the complex Yukawa coupling matrix. Our results provide a first step towards a seesaw benchmark model for further phenomenological studies and model building.
  • It is shown that type I seesaw models based on the standard model Lagrangian extended with three heavy Majorana right-handed fields do not have leptogenesis in leading order, if the symmetries of mass matrices are also the residual symmetry of the Lagrangian. In particular, flavor models that lead to a mass-independent leptonic mixing have a vanishing leptogenesis CP asymmetry. Based on symmetry arguments, we prove that in these models the Dirac-neutrino Yukawa coupling combinations relevant for leptogenesis are diagonal in the physical basis where the charged leptons and heavy Majorana neutrinos are diagonal.
  • Recent searches for first-generation leptoquarks and heavy right-handed W R bosons have seen excesses in final states with electrons and jets. A bizarre property of these excesses is that they appear to violate lepton universality. With these results in mind, we study the phenomenology of supersymmetric models in which the Higgs arises as the sneutrino in an electron supermultiplet. Since the electron is singled out in this approach, one can naturally account for the lepton flavor structure of the excesses. In this work, we show that in such a framework, one can significantly alleviate the tension between the Standard Modelmore » and the data and yet evade current constraints from other searches. Finally we point out that correlated excesses are expected to be seen in future multilepton searches.« less