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Related papers: Hard-Thermal-Loop Corrections in Leptogenesis I: C…

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Using the asymptotic-expansion technique, we compute the dominant two-loop electroweak corrections, of O(G_F m_t^2), to production and decay via a pair of photons or gluons of the CP-odd Higgs boson A^0 in a two-Higgs-doublet model with…

High Energy Physics - Phenomenology · Physics 2008-11-26 Joachim Brod , Frank Fugel , Bernd A. Kniehl

We consider a simple extension of the Standard Model by adding two Higgs triplets and a complex scalar singlet to its particle content. In this framework, the CP symmetry is spontaneously broken at high energies by the complex vacuum…

High Energy Physics - Phenomenology · Physics 2013-05-30 G. C. Branco , R. Gonzalez Felipe , F. R. Joaquim , H. Serodio

We calculate Boltzmann neutrino energy transport with self-consistently coupled nuclear reactions through the weak-decoupling-nucleosynthesis epoch in an early universe with significant lepton numbers. We find that the presence of lepton…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 E. Grohs , George M. Fuller , C. T. Kishimoto , Mark W. Paris

Polynomial inflation is a very simple and well motivated scenario. A potential with a concave ``almost'' saddle point at field value $\phi = \phi_0$ fits well the cosmic microwave background (CMB) data and makes testable predictions for the…

High Energy Physics - Phenomenology · Physics 2024-02-28 Manuel Drees , Yong Xu

We present a novel approach for implementing baryogenesis via leptogenesis at low scale within neutrino seesaw framework where a sufficient lepton asymmetry can be generated via out of equilibrium CP-violating decays of right handed…

High Energy Physics - Phenomenology · Physics 2026-04-14 Dipendu Bhandari , Arunansu Sil

In a general two Higgs doublet model, we study flavor changing neutral Higgs (FCNH) decays into leptons at hadron colliders, $pp \to \phi^0 \to \tau^\mp\mu^\pm +X$, where $\phi^0$ could be a CP-even scalar ($h^0$, $H^0$) or a CP-odd…

High Energy Physics - Phenomenology · Physics 2019-07-24 Wei-Shu Hou , Rishabh Jain , Chung Kao , Masaya Kohda , Brent McCoy , Amarjit Soni

A search for neutral long-lived particles (LLPs) decaying in the ATLAS hadronic calorimeter using 140 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV delivered by the LHC is presented. The analysis is composed of three channels.…

High Energy Physics - Experiment · Physics 2025-12-01 ATLAS Collaboration

We calculate the thermodynamic functions of a quark-gluon plasma for general N_c and N_f to three-loop order using hard-thermal-loop perturbation theory. At this order, all the ultraviolet divergences can be absorbed into renormalizations…

High Energy Physics - Phenomenology · Physics 2011-03-07 Jens O. Andersen , Lars E. Leganger , Michael Strickland , Nan Su

We demonstrate a unified scenario for neutrino mass, baryon asymmetry, dark matter and inflation. In addition to a fermion triplet for the so-called minimal dark matter, we extend the standard model by three heavy fields including a scalar…

High Energy Physics - Phenomenology · Physics 2017-01-25 Hang Zhou , Pei-Hong Gu

We comment on the recent paper by A. D. Dolgov, S. H. Hansen, S. Pastor and D. V. Semikoz (DHPS) [Astropart. Phys. {\bf 14}, 79 (2000)] on the generation of neutrino asymmetries from active-sterile neutrino oscillations. We demonstrate that…

High Energy Physics - Phenomenology · Physics 2011-05-23 P. Di Bari , R. Foot , R. R. Volkas , Y. Y. Y. Wong

Direct CP asymmetries and the CP violating normal polarization of lepton in inclusive decay B \to X_s l^+ l^- are investigated in minimal supergravity model with CP violating phases. The contributions coming from exchanging neutral Higgs…

High Energy Physics - Phenomenology · Physics 2009-10-31 Chao-Shang Huang , Liao Wei

We construct an effective action for "soft" gluons by integrating out hard thermal modes of topologically massive vector bosons at one loop order. The loop carrying hard gluons (momentum $\sim T$) are known as hard thermal loop (HTL). The…

High Energy Physics - Theory · Physics 2020-05-06 Debmalya Mukhopadhyay , R. Kumar , Jan-e Alam , Sushant K. Singh

The temperature of sphaleron freeze-out, $T\approx 130$ GeV, sets a scale for mechanisms for generating lepton asymmetries and converting them to baryon asymmetry (leptogenesis). For Majorana masses $M \gg \pi T$, leptogenesis takes place…

High Energy Physics - Phenomenology · Physics 2022-07-27 M. Laine

We study hypermagnetic helicity and lepton asymmetry evolution in plasma of the early Universe before the electroweak phase transition (EWPT) accounting for chirality flip processes via inverse Higgs decays and sphaleron transitions which…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 V. B. Semikoz , A. Yu. Smirnov , D. D. Sokoloff

We study hypermagnetic helicity and lepton asymmetry evolution in plasma of the early Universe before the electroweak phase transition (EWPT) accounting for chirality flip processes via inverse Higgs decays and sphaleron transitions which…

High Energy Physics - Phenomenology · Physics 2016-05-25 V. B. Semikoz , Alexander Yu. Smirnov , D. D. Sokoloff

CP violation from physics beyond the Standard Model is investigated in $B_{l4}$ decays: $B\to D\pi l\bar{\nu}_l$. In the decay process, we include various excited states as intermediate states decaying to the final hadrons, $D+\pi$. We…

High Energy Physics - Phenomenology · Physics 2016-08-25 C. S. Kim , Jake Lee , W. Namgung

We study the scenario of thermal leptogenesis in which the leptonic asymmetries are resonantly enhanced through the mixing of nearly degenerate heavy Majorana neutrinos that have mass differences comparable to their decay widths.…

High Energy Physics - Phenomenology · Physics 2011-05-05 Apostolos Pilaftsis , Thomas E. J. Underwood

Leptogenesis in supersymmetric model is discussed comprehensively and in detail. In the first half, we discuss several leptogenesis mechanisms by the decay of heavy right-handed neutrino, which include the standard thermal leptogenesis,…

High Energy Physics - Phenomenology · Physics 2007-05-23 K. Hamaguchi

Thermal leptogenesis is an attractive mechanism for generating the baryon asymmetry of the Universe. However, in supersymmetric models, the parameter space is severely restricted by the gravitino bound on the reheat temperature $T_{RH}$.…

High Energy Physics - Phenomenology · Physics 2010-02-03 Sacha Davidson

Since decays to four leptons is widely considered a promising way to search for the Higgs particle, we show how the same final state can also be used to search for signals of CP nonconservation. Energy asymmetries and triple correlations…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. Soni , R. M. Xu