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Related papers: CP-violating Majorana phases, lepton-conserving pr…

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In the minimal left-right symmetric model with spontaneous CP violation, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors. In addition, the left-and right-handed Majorana…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mu-Chun Chen , K. T. Mahanthappa

We analyze the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy Majorana neutrinos and pay special attention to CP violation. Extending a recently proposed resummation formalism for two-fermion…

High Energy Physics - Phenomenology · Physics 2014-11-17 Apostolos Pilaftsis

We discuss the process $\ell^+\ell^- \to N W^{\pm} \ell^{\mp}$, where $N$ is a heavy Majorana neutrino and $\ell = e, \mu$. Large cross sections are expected for these processes at high center-of-mass energies, which can be reached at…

High Energy Physics - Phenomenology · Physics 2023-09-29 E. Antonov , A. Drutskoy , M. Dubinin

In this paper, we carry out a systematic study of the sufficient and necessary conditions for CP conservation in the leptonic sector with massive Majorana neutrinos. In particular, the emphasis is placed on the number of CP-violating phases…

High Energy Physics - Phenomenology · Physics 2021-02-23 Bingrong Yu , Shun Zhou

We study the conditions under which the Majorana phase of the two flavor neutrino mixing matrix appears in the oscillation probabilities and causes $CP$ violation. We find that the Majorana phase remains in the neutrino evolution equation…

High Energy Physics - Phenomenology · Physics 2023-01-11 Khushboo Dixit , Akhila Kumar Pradhan , S. Uma Sankar

After discussion of mechanisms of lepton number violation, we consider meson decays $K^+ \to\pi^ - \ell ^ + \ell '^ +$ and $D^ + \to K^ - \ell ^ + \ell '^ +$ ($\ell,\ell ' = e,\mu $) with $\Delta L= 2$ in the Standard Model extended by…

High Energy Physics - Phenomenology · Physics 2011-12-20 A. V. Borisov

If the neutrino is a Majorana particle, low-energy lepton-number-violating (LNV) processes, such as neutrinoless double-beta ($0\nu\beta\beta$) decay, are possible. It may also be possible to observe high-energy $0\nu\beta\beta$-like LNV…

High Energy Physics - Phenomenology · Physics 2020-08-05 Fatemeh Najafi , Jacky Kumar , David London , Richard MacKenzie

The lepton number violating process, $e^- e^- \to W^- W^-$ has been widely discussed in the Majorana neutrino exchange mechanism. Here, we discuss this process in a composite neutrino model where excited Majorana neutrinos are exchanged. We…

High Energy Physics - Phenomenology · Physics 2009-10-31 Robert Kinyua , Eiichi Takasugi

The effective Majorana mass which determines the rate of the neutrinoless double beta decay, |<m>|, is considered in the case of three-neutrino mixing and massive Majorana neutrinos. Assuming a rather precise determination of the parameters…

High Energy Physics - Phenomenology · Physics 2011-04-20 S. Pascoli , S. T. Petcov , L. Wolfenstein

The scenario of baryogenesis through leptogenesis is reviewed in models involving heavy Majorana neutrinos. The various mechanisms of CP violation occurring in the out-of-equilibrium lepton-number-violating decays of heavy Majorana…

High Energy Physics - Phenomenology · Physics 2011-08-17 Apostolos Pilaftsis

We study CP asymmetries in lepton-number violating two-body scattering processes and show how they are related to CP asymmetries in the decays of intermediate massive Majorana neutrinos. Self-energy corrections, which do not contribute to…

High Energy Physics - Phenomenology · Physics 2009-10-30 W. Buchmuller , M. Plumacher

We have investigated an approach for determining the Majorana type-phases using the time evolution of lepton family numbers. We show how the second-order time derivative of the expectation values for the lepton family numbers depends on the…

High Energy Physics - Phenomenology · Physics 2025-03-04 Nicholas J. Benoit , Yuta Kawamura , Saki Hamada , Takuya Morozumi , Yusuke Shimizu , Kei Yamamoto

We investigate possible CP violating effects in $e^+e^-$ annihilation into top quark pairs. One of the interesting observable effects is the difference in production rates between the two CP conjugate polarized states $t_L\bar t_L$ and…

High Energy Physics - Phenomenology · Physics 2009-09-01 Darwin Chang , Wai-Yee Keung , Ivan Phillips

We study the relation between the Majorana neutrino mass matrices and the neutrinoless double beta decay when CP is not conserved. We give an explicit form of the decay rate in terms of a rephasing invariant quantity and demonstrate that in…

High Energy Physics - Phenomenology · Physics 2010-11-01 Patrick J. O'Donnell , Utpal Sarkar

The mass term for Majorana neutrinos explicitly violates lepton number. Several authors have used this fact to create a lepton asymmetry in the universe by considering CP violating effects in the one loop self-energy correction for the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Raghavan Rangarajan , Hiranmaya Mishra

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification…

High Energy Physics - Phenomenology · Physics 2014-11-17 Cheng-Wei Chiang

Heavy Majorana neutrinos beyond the standard model can simultaneously explain the origin of tiny neutrino masses and matter-antimatter asymmetry in our Universe. The existence of heavy Majorana neutrinos will also lead to lepton number…

High Energy Physics - Phenomenology · Physics 2022-10-05 Peng-Cheng Lu , Zong-Guo Si , Zhe Wang , Xing-Hua Yang

The tiny neutrino masses can be explained naturally by extending the standard model with right-handed Majorana neutrinos in low-scale seesaw mechanism, and the CP violation effect induced by Majorana phase is interesting and worth studying…

High Energy Physics - Phenomenology · Physics 2021-10-22 Peng-Cheng Lu , Zong-Guo Si , Zhe Wang , Xing-Hua Yang

We study the Lepton number violating like-sign dilepton processes $h_1 h_2 \to l^\pm l^{\prime \pm} jj X$ and $h_1 h_2 \to l^\pm l^{\prime \pm} W^\pm X$, mediated by heavy GeV scale Majorana neutrinos. We focus on the resonantly enhanced…

High Energy Physics - Phenomenology · Physics 2009-11-05 Sergey Kovalenko , Zhun Lu , Ivan Schmidt

In this letter we give a class of examples where the decays of the heavy Majorana neutrinos may violate CP even if there is no CP violation at low energies, i.e., leptogenesis can take place without Majorana or Dirac type CP phases at low…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. N. Rebelo