7,048 research outputs found
One-loop running of dimension-six Higgs-neutrino operators and implications of a large neutrino dipole moment
No full textWe compute the one-loop running of the dimension-six CP-even Higgs operators in the Standard Model effective field theory involving the right-handed component of the would-be Dirac neutrinos. Then, on the basis of naturalness arguments, for some operators we obtain bounds that surpass direct constraints by orders of magnitude. We also discuss the implications of a large Dirac neutrino magnetic dipole moment. In particular, we demonstrate that a neutrino magnetic moment explaining the recent XENON1T excess induces Higgs and Z invisible decays with branching ratios in the range [10(-18), 10(-12)]. These numbers are unfortunately beyond the reach of current and near future facilities
Neutrino masses in the Standard Model effective field theory
No full textWe compute the leading-logarithmic correction to the neutrino mass matrix in the Standard Model effective field theory (SMEFT) to dimension seven. In the limit of negligible lepton and down-type quark Yukawa couplings, it receives contributions from the Weinberg dimension-five operator as well as from 11 dimension-six and five dimension-seven independent interactions. Two of the main implications we derive from this result are the following. First, we find dimension-seven operators which, despite violating lepton number, do not renormalize neutrino masses at one loop. And second, we demonstrate that the presence of dimension-six operators around the TeV scale can modify the Standard Model prediction by up to O(50%). Our result comprises also one step forward towards the renormalization of the SMEFT to order v(3)/Lambda(3)
Euchalcia matovi Volynkin & Titov, sp. n.
No full textEuchalcia matovi Volynkin & Titov, sp. n. (Figs 1–5, 11, 12, 17, 18, 22) Type material. Holotype: male, 09.vi. 2013, E Kazakhstan, East Kazakhstan area, Urdzhar district, Tarbagatai Ridge, 6.7 km N of Kyzymbet (Alekseevka) village, mesophilous shrubby slopes, 1300 m. 47 ° 18.365 ’ N, 81 ° 32.152 ’ E, Volynkin A.V., Titov S.V. & Černila M. leg. Slide AV0865 Volynkin (Coll. ZISP). Paratypes: 22 males, 15 females, with the same labels as holotype, slides AV0853, AV0863, AV0864, AV0870, AV0871, AV0872, AV0873, AV0874 Volynkin (males), AV0866, AV0867, AV 1177, AV 1178 Volynkin (females) (Colls ZISP, AVB, STP, MČK); 2 females, 9.vii. [19] 67, Kazakhstan, Dzhungarsky Alatau, I. Kostin [leg.] / Euchalcia inconspicua, Zolotarenko det., slides AV 1177, AV 1178 Volynkin (females) (Coll. SZMN). Diagnosis. The new species is the third and the smallest member of the E. inconspicua species-complex. Externally E. matovi (Figs 1–5) is close to E. anthea (Figs 9, 10), but differs from it by smaller size (wingspan of E. anthea 31–36 mm), somewhat paler, more brilliant forewing colouration and less contrast pattern; from E. inconspicua (Figs 7, 8) differs by smaller size (wingspan of E. inconspicua 32–37 mm), broader forewing in females, with less acutely pointed apex of forewing in both sexes, much paler forewing colouration with paler medial field and less contrast pattern. E. matovi is also externally similar to E. shugnana (Sheljuzhko, 1929) (Fig. 6), but differs from it by somewhat less acutely pointed apex of forewing in both sexes, broader forewing in females, more brilliant forewing colouration. The male genitalia of the new species (Figs 11, 12) are close to those of E. inconspicua (Figs 13, 14). The genital capsule of E. matovi differs by longer and narrower uncus, narrower and distally more angled valva with larger ventro-medial triangular lobes; E. matovi has a larger aedeagus in comparison to the genital capsule of E. inconspicua, the vesica of E. matovi is longer, and subterminal cornuti are somewhat longer and more to robust. From E. anthea (Fig. 15) the male genitalia of E. matovi differ by medially broader valva with larger ventro-medial triangular lobes, somewhat longer aedeagus in comparison with the genital capsule, shorter and broader basal tube of vesica, and longer and stronger subterminal cornuti; from E. shugnana (Fig. 16) the male genitalia differ by longer uncus, longer harpe and the vesica structure: in E. matovi the basal tube is much longer, subterminal cornuti longer and stronger. The female genitalia of E. matovi (Figs 17, 18) differ from those of E. inconspicua (Fig. 19) by longer ductus bursae with much stronger sclerotised bulbous anterior part; from E. anthea (Fig. 20) differ by shorter and not S-shaped ductus bursae and somewhat stronger sclerotised bulbous anterior part; from E. shugnana (Fig. 21) differ by much larger, more rounded anterior part of ductus bursae, larger appendix bursae, longer corpus bursae. Description. Adult (Figs 1–5, 22). Wingspan 28–31 mm, length of forewing 12–14 mm. Antennae filiform. Head, thorax and abdomen ochreous; tegulae and patagia golden ochreous; Forewing broad, with pointed apex. Ground colour of forewing ochreous with metallic golden sheen; basal line thin, brown, wavy, indistinct; antemedial and postmedial lines thin, dark golden brown; antemedial line bent at A 1, postmedial line smooth curved; suffusion of the medial area varies from golden ochreous to golden brown; submarginal line thin, smooth curved, dark golden brown, with conspicuous dark golden brown shadow at inner margin; terminal line thin, dark brown; cilia ochreous or brown; orbicular, reniform and subcellular stigma conspicuous, with thin dark brown borders. Hindwing ochreous or ochreous brown; terminal band wide, dark, fuzzy; medial band thin, slightly wavy, dark brown; discal spot thin, brown, indistinct. Male genitalia (Figs 11, 12). Uncus narrow, long, curved, apically pointed; tegumen broad, moderately long; juxta broad, shield-like, with long conical apical process; vinculum long, V-shaped; valva moderately broad, distally narrowed, angled, with well developed ventro-medial triangular lobes; sacculus relatively small, clavus small, short, triangular; harpe long, thin; aedeagus large, moderately broad; vesica tubular, consists of broad tubular basal part and sphaerical subterminal bulb with three-six large subterminal cornuti and one terminal cornutus. Female genitalia (Figs 17, 18). Ovipositor short, conical. Apophyses posteriores and anteriores long, thin. Ostium bursae membranous; ductus bursae moderately long, tubular, rugose, with strongly sclerotised bulbous proximal plate at junction to corpus bursae; appendix bursae small, elliptical, membranous; ductus bursae membranous, sack-like, moderately long. Distribution and bionomics. The new species is known from the south-west part of Tarbagatai Ridge in East Kazakhstan and the Dzhungarsky Alatau Mts. in South-East Kazakhstan. At the type locality, E. matovi inhabits mesophilous slopes with Lonicera and Rosa shrubs (Fig. 23). Etymology. The species name is dedicated to Dr. Alexey Matov (ZISP), an expert on Asian Noctuoidea.Published as part of Volynkin, Anton V., Titov, Sergey V. & Ivanova, Maria S., 2014, A new species of Euchalcia Hübner, [1821] from Kazakhstan (Lepidoptera, Noctuidae), pp. 493-497 in Zootaxa 3784 (4) on pages 493-497, DOI: 10.11646/zootaxa.3784.4.8, http://zenodo.org/record/22799
Perigrapha (Perigrapha) yasawii Volynkin, Titov & Knyazev, sp. n.
No full textPerigrapha (Perigrapha) yasawii Volynkin, Titov & Knyazev, sp. n. (Figs 1–3, 11, 12) Type material. Holotype: male, 14.iv. 2014, S Kazakhstan, South Kazakhstan Region, 39 km WSW of Turkestan city, Syrdarya river valley, h= 180 m, N 43 ° 10.006 ’, E 67 ° 50.389 ’, at light. Volynkin A.V., Titov S.V. & Knyazev S.A. leg. Slide AV 1242 Volynkin (Coll. Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia [ZISP]). Paratypes: 26 males, with the same data as holotype (Colls A. Volynkin, Barnaul, Russia [AVB]; S. Knyazev, Omsk, Russia [SKO]; S. Titov, Pavlodar, Kazakhstan [STP]; ZISP); 1 male, Perovsk [S Kazakhstan, Kyzyl-Orda Region, vicinity of Kyzyl-Orda city], Syr-Darya reg., 2.iv. 1909, E. Miller [leg.] (Coll. ZISP). Slides AV 1230, AV 1243 Volynkin (males). Diagnosis. The new species belongs to P. circumducta complex of the P. i-cinctum ([Denis & Schiffermüller], 1775) species-group including P. sechuana G. Ronkay, L. Ronkay & Hacker, 2010, P. circumducta circumducta (Lederer, 1855) and P. circumducta pallescens (Draudt 1934) (Hreblay 1996; Ronkay et al. 2001; Ronkay et al. 2010). P. yasawii sp. n. (Figs 1–3) differs externally from P. circumducta circumducta (Figs 4–6) by its somewhat smaller size (wingspan of P. circumducta circumducta 42–53 mm), broader pectination of male antennae, more concolorous brownish-grey ground colour of forewings (in P. c. circumducta ground colour varies from reddishbrown to blackish-brown), pale subbasal area, pale subterminal area with narrower dark field outwards the postmeidal line, somewhat smaller orbicular stigma, more rounded reniform stigma, much narrower suborbicular patch and more greyish hindwings; from P. circumducta pallescens (Figs 7, 8) by its smaller size, broader pectination of male antennae, brownish-grey ground colour of forewings, more concolorous subterminal area with narrower dark field outwards the postmeidal line, more rounded reniform stigma, much narrower suborbicular patch and more greyish hindwings; from P. sechuana (Figs 9, 10) by its smaller size, narrower forewings, concolorous brownish-grey ground colour of forewings (in P. sechuana ground colour reddish-brown), paler subbasal area, pale subterminal area with narrower dark field outwards the postmeidal line, somewhat smaller orbicular stigma, more rounded reniform stigma, much narrower suborbicular patch and less unicolorous, more greyish hindwings with paler basal area. The male genitalia of P. yasawii sp. n. (Figs 11, 12) differ from those of P. circumducta (Figs 13) by the proximally broader, almost quadrangular uncus, more quadrangular juxta, broader clasper with shorter harpe and broader proximal part of ampulla; from P. sechuana (Fig. 14) by proximally broader, almost quadrangular uncus, broader clasper with shorter harpe, less asymmetrical and apically more dilated distal parts of valvae, longer aedeagus and much longer, less dorsally recurved vesica. Description. Adult (Figs 1–3). Male. Wingspan 37–43 mm. Antennae bipectinate, with long branches. Head, thorax and abdomen brownish-grey. Ground colour of forewing pale brownish-grey, medial area dark, greyishbrown, paler near the costal margin; antemedial and postmedial lines thin, dark grey; antemedial line almost straight, slightly curved near the costal margin; postmedial line almost straight, only arcuate around the cell; subterminal line indistinct; terminal area darker than subterminal; terminal line blackish, divided into short spots; orbicular and reniform stigmata and suborbicular patch being connected with reniform stigma with merged edges, pale greyish-ochreous, bordered with blackish; cilia grey. Hindwing greyish-brown; discal spot and medial line indistinct, dark; cilia dark grey. Female unknown. Male genitalia (Figs 11, 12). Uncus short, almost quadrangular, apically slightly rounded; tegumen short, weak; penicular lobes weak, narrow; juxta long, almost quadrangular; vinculum short, V-shaped; valva long, relatively narrow; cuculli long, straight, narrow, without pollex-like extensions, asymmetrical; distal part of left cucullus longer, apically narrower than that of right cucullus; ampulla long, slender, moderately curved, apically pointed; clasper short, distally strongly broadened, harpe very short; aedeagus very long, curved; vesica long, twisted, with subconical medial diverticulum with very small field of weak and short spinules, and large terminal field of spinules on broad diverticulum. Distribution and bionomics. The new species is known from two localities in South Kazakhstan. P. y as a w i i sp. n. inhabits dry shrubby river valleys (Fig. 15). Etymology. The species name is dedicated to Khodja Ahmed Yasawi, a Turkic poet and Sufi, whose mausoleum is in Turkestan city, less than 40 km from the type locality.Published as part of Volynkin, Anton V., Titov, Sergey V. & Knyazev, Svyatoslav A., 2014, A new Perigrapha Lederer, 1857 from South Kazakhstan (Lepidoptera, Noctuidae), pp. 292-296 in Zootaxa 3856 (2) on pages 292-296, DOI: 10.11646/zootaxa.3856.2.8, http://zenodo.org/record/22497
Effective field theory for vector-like leptons and its collider signals
No full textWe argue that in models with several high scales; e.g. in composite Higgs models or in gauge extensions of the Standard Model (SM), vector-like leptons can be likely produced in a relatively large root s region of the phase space. Likewise, they can easily decay into final states not containing SM gauge bosons. This contrasts with the topology in which these new particles are being searched for at the LHC. Adopting an effective field theory approach, we show that searches for excited leptons must be used instead to test this scenario. We derive bounds on all the relevant interactions of dimension six; the most constrained ones being of about 0.05 TeV-2. We build new observables to improve current analyses and study the impact on all single-field UV completions of the SM extended with a vector-like lepton that can be captured by the effective field theory at tree level, in the current and in the high-luminosity phase of the LHC. (C) 2020 The Author(s). Published by Elsevier B.V
Predictions for the Majorana CP violation phases in the neutrino mixing matrix and neutrinoless double beta decay
No full textAbstractWe obtain predictions for the Majorana phases α21/2 and α31/2 of the 3×3 unitary neutrino mixing matrix U=Ue†Uν, Ue and Uν being the 3×3 unitary matrices resulting from the diagonalisation of the charged lepton and neutrino Majorana mass matrices, respectively. We focus on forms of Ue and Uν permitting to express α21/2 and α31/2 in terms of the Dirac phase δ and the three neutrino mixing angles of the standard parametrisation of U, and the angles and the two Majorana-like phases ξ21/2 and ξ31/2 present, in general, in Uν. The concrete forms of Uν considered are fixed by, or associated with, symmetries (tri-bimaximal, bimaximal, etc.), so that the angles in Uν are fixed. For each of these forms and forms of Ue that allow to reproduce the measured values of the three neutrino mixing angles θ12, θ23 and θ13, we derive predictions for phase differences (α21/2−ξ21/2), (α31/2−ξ31/2), etc., which are completely determined by the values of the mixing angles. We show that the requirement of generalised CP invariance of the neutrino Majorana mass term implies ξ21=0 or π and ξ31=0 or π. For these values of ξ21 and ξ31 and the best fit values of θ12, θ23 and θ13, we present predictions for the effective Majorana mass in neutrinoless double beta decay for both neutrino mass spectra with normal and inverted ordering
Measurement of the electron's electric dipole moment using YbF molecules: methods and data analysis
No full text21.06.13 KB. Ok to add the author accepted version to spiral. IO
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