Gauge dependence of tadpole and mass renormalization for a seesaw extended 2HDM

We study the gauge dependence of the neutrino mass renormalization in a two Higgs doublet model, that is extended with one singlet seesaw neutrino. This model gives only one light neutrino a mass at tree level, while the second light mass is generated at loop level via the interaction with the second Higgs doublet. At one loop level, one neutrino stays massless. We use multiplicative renormalization constants to define counterterms. The renormalized mass parameters are defined as the complex poles of the propagators, using the complex mass scheme for mass renormalization. With this setup, we analytically get the expressions for the neutrino mass counterterms and isolate the gauge dependent part. We show, how relating this gauge dependent part with the tadpole renormalization leads to gauge independent counterterm definitions, hence gauge independent bare masses for neutrinos.Comment: 12 pages; v2: added 2 references and corrected 2 typos: indexes in eq.(3) and on page 9 (the the -> that the

Vacuum expectation value renormalization in the Standard Model and beyond

We show how the renormalization constant of the Higgs vacuum expectation value, fixed by a tadpole condition, is responsible for gauge dependences in various definitions of parameters in the $R_{\xi}$-gauge. Then we show the relationship of this renormalization constant to the Fleischer-Jegerlehner (FJ) scheme, which is used to avoid these gauge dependences. In this way, we also present a viewpoint on the FJ-scheme complementary to the ones already existing in the literature. Additionally, we compare and discuss different approaches to the renormalization of tadpoles by identifying the similarities and relations between them. The relationship to the Higgs background field renormalization is also discussed.Comment: 16 pages; accepted for publication in pr

Charged lepton flavor violating processes in the Grimus-Neufeld model

Charged Lepton Flavour Violating (cLFV) decays constrain the relationship between the neutrino and the scalar sectors of the Grimus-Neufeld model (GNM), an appealing minimal model of neutrino masses. It turns out, that in the scenario, where the seesaw scale is lower than the electroweak one, cLFV is completely defined by the new Yukawa interactions between the additional single heavy Majorana neutrino, the second Higgs doublet and the lepton doublets. Therefore, we derive a useful parameterization for the Yukawa couplings which reproduces by construction the correct PMNS matrix and the correct neutrino masses for both Normal and Inverted ordering at one-loop level. We embed this scenario in the $\texttt{FlexibleSUSY}$ spectrum-generator generator to perform parameter scans. Focusing on the tiny seesaw scale, we show that current $\mu\to e\gamma$ limits provide significant constraints on the scalar sector, and we evaluate the impact of future cLFV $\tau$-decay searches for the cases of discovery or non-discovery. The tiny seesaw scale makes the neutrino sector and the cLFV processes in the GNM similar to the scotogenic and the scoto-seesaw models, so we provide constraints for these models as well.Comment: updated to match the published version + misprint in eq.(5.1) fixe

Pulmonary Involvement in Echinococcosis

Aim of the study: Discover the rate of pulmonary involvement in patients treated for echinococcosis during the period of 2009-2019 in LSMU hospital Kauno Klinikos and evaluate the characteristics of pulmonary lesions. Objectives: 1. Discover the organ involvement distribution of echinococcosis and compare the results with previous publications. 2. Ascertain the characteristics of pulmonary involvement of echinococcosis. 3. Determine whether there is a correlation between multiple organ involvement and positive serological test results. Methods: A retrospective study was conducted in the Department of Radiology of LSMU hospital Kaunas Clinics. Medicinal documents of patients treated for echinococcosis in the years 2009 to 2019 were assessed. Results: 102 cases were discovered. Pulmonary involvement has been discovered in 4,8% of all cases, in 8% of E. granulosus infection cases and in 4,6% of E. multilocularis infection cases. The characteristics of lung lesions were determined by the species of echinococcus. E. granulosus cases presented as solitary, well defined, thick walled cystic lesions up to 4 cm in diameter; E. multilocularis cases presented as multiple lesions of various forms up to 1,5 cm in diameter, which were located in multiple lobes in one or both lungs. In cases where only the liver was involved, a positive serological test result was found in 66,7% of the cases, while in multiple organ involvement cases positive results were found in 90,0% of the cases. No statistical difference was found between these 2 groups. It was noticed that in some cases E. multilocularis infection was diagnosed without test results supporting it. Conclusions: 1. It was discovered that the organ involvement of echinococcosis in our study does not match the results of other publications. 2. E. granulosus cases presented as solitary, well defined cystic lesions in the lungs, while E. multilocularis cases presented as multiple, irregularly shaped and ill defined lesions spread in multiple lobes. 3. No correlation was found between multiple organ involvement and positive serological test results. Practical recommendations: 1. We suggest that radiological evaluation of the chest should always follow a diagnosis of echinococcosis due to the possibility of pulmonary involvement. 2. We recommend exercising caution and relying on radiologic and serologic test results when formulating a clinical diagnosis of echinococcosis, as the course of disease and treatment guidelines are different in E. granulosus and E. multilocularis cases

Neutrino masių pernormavimas Grimus-Neufeld modelyje

We study the gauge dependence of the renormalization of neutrino masses in the Grimus-Neufeld (GN) model. We apply the complex mass scheme (CMS) in order to get gauge invariant renormalized masses. Despite solving the problem of gauge dependence in the definitions of renormalized masses, the CMS does not ensure that both bare and renormalized masses are gauge invariant. We trace the roots of this problem back to the interplay between the renormalization of the Higgs vacuum expectation value (VEV) and the renormalization of mass. We then apply the Fleischer-Jegerlehner (FJ) scheme in addition to the CMS, to the renormalization of neutrino masses in the GN model. We show, that the FJ scheme defines gauge invariant bare and renormalized masses by exploiting the connection with the renormalization of the Higgs VEV. To explicitly check that our expressions are gauge invariant, we use the Mathematica packages SARAH, FeynArts and FormCalc. We thoroughly describe our set up, so that our results can be easily checked and reproduced

Low seesaw scale in the Grimus–Neufeld model /

We present the possibility of the low seesaw scenario in the Grimus-Neufeld model. We argue that it can be natural and phenomenologically interesting, while consistent with neutrino data. We present the approximated expressions for neutrino masses and estimate the magnitude of the Yukawa couplings. We show that they can be sizable and can lead to possible restrictions on the scalar sector

On the renormalization of neutrinos in the seesaw extension of the two-Higgs doublet model

We present the complex mass renormalization scheme for mixed Majorana fermions using the Weyl spinor notation. Showing the expressions for field and mass renormalization constants, we discuss the differences to the on-shell renormalization scheme. Working in a seesaw extended two-Higgs doublet model, we apply the complex mass scheme for neutrino masses and mixings

Search for supersymmetry in events with a photon, a lepton, and missing transverse momentum in proton-proton collisions at √s= 13 TeV

Results of a search for supersymmetry are presented using events with a photon, an electron or muon, and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 35.9 fb⁻¹ of proton-proton collisions at √s=13 TeV, produced by the LHC and collected with the CMS detector in 2016

Search for heavy resonances decaying into two Higgs bosons or into a Higgs boson and a W or Z boson in proton-proton collisions at 13 TeV

A search is presented for massive narrow resonances decaying either into two Higgs bosons, or into a Higgs boson and a W or Z boson. The decay channels considered are HH→bb¯τ⁺τ⁻ and VH→qq¯τ⁺τ⁻, where H denotes the Higgs boson, and V denotes the W or Z boson. This analysis is based on a data sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV by the CMS Collaboration, corresponding to an integrated luminosity of 35.9 fb⁻¹

Search for heavy Majorana neutrinos in same-sign dilepton channels in proton-proton collisions at √s=13 TeV

A search is performed for a heavy Majorana neutrino (N), produced in leptonic decay of a W boson propagator and decaying into a W boson and a lepton, with the CMS detector at the LHC. The signature used in this search consists of two same-sign leptons, in any flavor combination of electrons and muons, and at least one jet. The data were collected during 2016 in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb⁻¹