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Sep 19, 2013
09/13

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F. del Aguila; J. A. Aguilar-Saavedra; R. Pittau

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We study the LHC discovery potential for heavy Majorana neutrino singlets in the process pp -> W+ -> l+ N -> l+ l+ jj (l=e,mu) plus its charge conjugate. With a fast detector simulation we show that backgrounds involving two like-sign charged leptons are not negligible and, moreover, they cannot be eliminated with simple sequential kinematical cuts. Using a likelihood analysis it is shown that, for heavy neutrinos coupling only to the muon, LHC has 5 sigma sensitivity for masses up to...

Source: http://arxiv.org/abs/hep-ph/0703261v4

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Jul 20, 2013
07/13

by
F. del Aguila; J. A. Aguilar-Saavedra

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We discuss the existing limits on top flavour-changing neutral couplings in models with new vector-like quarks. Large hadron and e+ e- colliders can improve these bounds by more than one order of magnitude.

Source: http://arxiv.org/abs/hep-ph/9906461v1

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Sep 19, 2013
09/13

by
F. del Aguila; M. Perez-Victoria; Jose Santiago

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We analyse the effect of general brane kinetic terms for bulk scalars, fermions and gauge bosons in theories with extra dimensions, with and without supersymmetry. We find in particular a singular behaviour when these terms contain derivatives orthogonal to the brane. This is brought about by $\delta(0)$ divergences arising at second and higher order in perturbation theory. We argue that this behaviour can be smoothed down by classical renormalization.

Source: http://arxiv.org/abs/hep-th/0302023v2

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42

Sep 22, 2013
09/13

by
F. del Aguila; J. Santiago

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Multilocalization provides a simple way of decoupling the mass scale of new physics from the compactification scale of extra dimensions. It naturally appears, for example, when localization of fermion zero modes is used to explain the observed fermion spectrum, leaving low energy remnants of the geometrical origin of the fermion mass hierarchy. We study the phenomenology of the simplest five dimensional model with order one Yukawa couplings reproducing the standard fermion masses and mixing...

Source: http://arxiv.org/abs/hep-ph/0111047v2

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Sep 22, 2013
09/13

by
F. del Aguila; J. Santiago

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We review how top mixing with light quarks constrains new physics beyond the Standard Model using the effective Lagrangian approach.

Source: http://arxiv.org/abs/hep-ph/0011142v1

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Sep 19, 2013
09/13

by
F. del Aguila

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All couplings of a new heavy gauge boson to ordinary fermions can be determined in a model-independent way at a large $e^+e^-$ collider for large enough statistics. No such determination is possible at LEP 200, however, because its design integrated luminosity is too low for existing and forthcoming limits on $Z'$ interactions. At any rate, it should be possible to distinguish between models for $Z'$ masses $ < 1\ TeV$, or to set limits of this order on $Z'$ masses for definite models. These...

Source: http://arxiv.org/abs/hep-ph/9405302v1

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Jul 20, 2013
07/13

by
F. del Aguila; J. A. Aguilar-Saavedra; Ll. Ametller

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Associated single top production with a Z boson or a photon at large hadron colliders provides a precise determination of top flavour-changing neutral couplings. The best way to measure these couplings with the up quark at Tevatron is to search for events with three jets and missing energy or events with a photon, a charged lepton, a jet and missing energy. Other decay channels are also discussed.

Source: http://arxiv.org/abs/hep-ph/9906462v4

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Sep 19, 2013
09/13

by
F. del Aguila; Ll. Ametller; R. Pittau

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We consider the next-to-leading order corrections, O(alpha_s), to forward-backward charge asymmetries for lepton-pair production in association with a large transverse momentum jet at large hadron colliders. We find that the leading order results are essentially confirmed. Although experimentally challenging and in practice with large backgrounds, these observables could provide a new determination of the weak mixing angle sin2 theta^lept_eff (M_Z^2) with a statistical precision for each lepton...

Source: http://arxiv.org/abs/hep-ph/0507262v2

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Sep 23, 2013
09/13

by
R. Pittau; F. del Aguila; Ll. Ametller

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The large cross sections for gauge boson production at the Fermilab Tevatron and the CERN Large Hadron Collider (LHC) might give a chance to determine the electroweak parameters with high precision. We calculated two different forward-backward charge asymmetries (A^CS_FB and A^j_FB) of lepton pairs in events with a large transverse momentum jet p p (pbar) -> Z, gamma* + j -> e- e+ j at next-to-leading order (NLO), O(alpha_s) corrections, making use of the Monte Carlo programs MCFM and...

Source: http://arxiv.org/abs/hep-ph/0511243v1

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Sep 19, 2013
09/13

by
M. Cvetic; F. del Aguila; P. Langacker

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We present recent developments in the diagnostic study of heavy gauge bosons at future colliders with the emphasis on the determination of gauge couplings of $Z'$ to quarks and leptons. Proposed diagnostic probes at future hadron colliders are discussed. The study of statistical uncertainties expected for the above probes at the LHC and $M_{Z'}\simeq 1$ TeV shows that three out of four normalized couplings can be determined, thus allowing for a distinction between models. The complementary...

Source: http://arxiv.org/abs/hep-ph/9309271v1

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Sep 23, 2013
09/13

by
F. del Aguila; J. A. Aguilar Saavedra; J. de Blas; M. Zralek

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Any new neutrino physics at the TeV scale must include a suppression mechanism to keep its contribution to light neutrino masses small enough. We review some seesaw model examples with weakly broken lepton number, and comment on the expected effects at large colliders and in neutrino oscillations.

Source: http://arxiv.org/abs/0710.2923v2

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Sep 18, 2013
09/13

by
F. del Aguila; M. Perez-Victoria

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We review the method of differential renormalization, paying special attention to a new constrained version for symmetric theories.

Source: http://arxiv.org/abs/hep-ph/9710442v1

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Jul 19, 2013
07/13

by
F. del Aguila; J. de Blas; M. Perez-Victoria

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We study extensions of the Standard Model with general new vector bosons. The full Standard Model gauge symmetry is used to classify the extra vectors and constrain their couplings. We derive the corresponding effective Lagrangian, valid at energies lower than the mass of the extra vectors, and use it to extract limits from electroweak precision observables, including LEP 2 data. We consider both universal and nonuniversal couplings to fermions. We study the interplay of several extra vectors,...

Source: http://arxiv.org/abs/1005.3998v2

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Sep 18, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra

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We find a minimal set of constraints which are independent of the choice of weak quark basis and necessary and sufficient for CP conservation for four quark families, including also the case of degenerate quark masses. These invariant conditions are written in the mass eigenstate basis as a function of the fermion masses and charged current mixings. CP violation is then related to the areas of three unitarity quadrangles and the CP violating effects of the fourth family are discussed in the...

Source: http://arxiv.org/abs/hep-ph/9605418v2

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Sep 23, 2013
09/13

by
F. del Aguila; J. I. Illana; M. D. Jenkins

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Little Higgs models provide a natural explanation of the little hierarchy between the electroweak scale and a few TeV scale, where new physics is expected. Under the same inspiring naturalness arguments, this work completes a previous study on lepton flavor-changing processes in the Littlest Higgs model with T-parity exploring the channel that will eventually turn out to be the most sensitive, \mu-e conversion in nuclei. All one-loop contributions are carefully taken into account, results for...

Source: http://arxiv.org/abs/1006.5914v2

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Sep 19, 2013
09/13

by
F. del Aguila; M. Martinez; M. Quiros

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We perform a fit to precise electroweak data to determine the Higgs and top masses. Penalty functions taking into account their production limits are included. We find ${\displaystyle m_H=65^{+245}_{-4}\ GeV}$ and ${\displaystyle m_t=122^{+25}_{-20}\ GeV}$. However whereas the top $\chi^2$ distribution behaves properly near the minimum, the Higgs $\chi^2$ distribution does not, indicating a statistical fluctuation or new physics. In fact no significative bound on the Higgs mass can be given at...

Source: http://arxiv.org/abs/hep-ph/9203210v1

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Sep 22, 2013
09/13

by
F. del Aguila; M. Perez-Victoria; J. Santiago

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In theories with branes, bulk fields get in general divergent corrections localized on these defects. Hence, the corresponding brane terms are renormalized and should be included in the effective theory from the very beginning. We review the phenomenology associated to brane kinetic terms for different spins and backgrounds, and point out that renormalization is required already at the classical level.

Source: http://arxiv.org/abs/hep-ph/0310352v1

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Sep 22, 2013
09/13

by
F. del Aguila; J. I. Illana; M. D. Jenkins

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We recalculate the leading one-loop contributions to mu > e gamma and mu -> eee in the Littlest Higgs model with T-parity, recovering previous results for the former. When all the Goldstone interactions are taken into account, the latter is also ultraviolet finite. The present experimental limits on these processes require a somewhat heavy effective scale ~2.5 TeV, or the flavour alignment of the Yukawa couplings of light and heavy leptons at the ~10% level, or the splitting of heavy...

Source: http://arxiv.org/abs/0811.2891v3

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42

Sep 20, 2013
09/13

by
F. del Aguila; R. Pittau

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A numerical approach to compute tensor integrals in one-loop calculations is presented. The algorithm is based on a recursion relation which allows to express high rank tensor integrals as a function of lower rank ones. At each level of iteration only inverse square roots of Gram determinants appear. For the phase-space regions where Gram determinants are so small that numerical problems are expected, we give general prescriptions on how to construct reliable approximations to the exact result...

Source: http://arxiv.org/abs/hep-ph/0404120v2

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Sep 19, 2013
09/13

by
F. del Aguila; M. Cvetic; P. Langacker

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We review present Z' bounds, discuss future Z' constraints from TEVATRON, HERA and LEP, and give a brief review of the Z' diagnostics at future colliders.

Source: http://arxiv.org/abs/hep-ph/9309222v1

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35

Sep 20, 2013
09/13

by
F. del Aguila; R. Pittau

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New large colliders will probe scales up to few TeV, indicating the way Nature has chosen to extend the Standard Model. We review alternative scenarios to the traditional Minimal Supersymmetric Standard Model: the little Higgs model, split supersymmetry and extra dimensional models with low energy signals.

Source: http://arxiv.org/abs/hep-ph/0410256v2

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Sep 17, 2013
09/13

by
F. del Aguila; M. Perez-Victoria; J. Santiago

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In theories with extra dimensions there are generically brane kinetic terms for fields living in the bulk. These modify the masses and wave functions of the Kaluza-Klein expansions, and then the effective four dimensional gauge and Yukawa couplings of the corresponding modes. Here, we discuss some phenomenological consequences of fermion brane kinetic terms, emphasizing their implications for models with low compactification scales, whose agreement with experiment can be improved, and...

Source: http://arxiv.org/abs/hep-ph/0305119v1

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Sep 20, 2013
09/13

by
F. del Aguila; M. Masip; M. Perez-Victoria

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We analize the structure of models with unbroken and spontaneously broken U(1)_a x U(1)_b gauge symmetry. We show that the quantum corrections to the 2N gauge charges, with N = #fermions + #scalars, can be absorbed in the redefinition of three independent gauge couplings (g_a,g_b and g_ab). We establish the (one-loop) conditions on the matter cotent for g_ab= = 0 (a value usually assumed in the literature) and we show that in the minimal extensions of the Standard Model with an extra U(1)...

Source: http://arxiv.org/abs/hep-ph/9507455v2

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31

Sep 19, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra; J. de Blas

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The comparison of samples with different number of charged leptons shows that trilepton signals are the most significant ones for seesaw mediators. As previously pointed out, this is indeed the case for scalar (type II) and fermion (type III) triplets at LHC, which can be discovered in this channel for masses up to 500-700 GeV and an integrated luminosity of 30 fb^-1; whereas fermion singlets (type I) are marginally observable if there are no further new physics near the TeV scale. However, if...

Source: http://arxiv.org/abs/0910.2720v1

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37

Sep 18, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra; R. Pittau

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Large colliders are not sensitive to light neutrino masses and character, but they can produce new heavy neutrinos, allowing also for the determination of their Dirac or Majorana nature. We review the discovery limits at the next generation of large colliders.

Source: http://arxiv.org/abs/hep-ph/0606198v2

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47

Sep 23, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra

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Zt and gamma t production with Z -> l+ l- and t -> Wb -> l nu b provides the best determination of top flavour-changing neutral couplings at the LHC. The bounds on tc couplings eventually derived from these processes are similar to those expected from top decays, while the limits on tu couplings are better by a factor of two. The other significant Z and W decay modes are also investigated.

Source: http://arxiv.org/abs/hep-ph/9909222v2

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27

Sep 21, 2013
09/13

by
F. del Aguila; M. Cvetic

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We study the diagnostic power of future $e^+e^-$ colliders with ${\sqrt {s}} = 500$ GeV (the New Large Collider ($NLC$)) for a model independent determination of the $Z'$ gauge couplings to quarks and leptons. The interference of the $Z'$ propagator with the photon and the $Z$ propagator in the two-fermion final state probes are sensitive to the magnitude as well as relative signs of quark and lepton charges. For $Z'$ with $M_{Z'} \sim 1 $ TeV {\it all } the quark and lepton charges can be...

Source: http://arxiv.org/abs/hep-ph/9312329v2

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49

Sep 18, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra

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Models of type I seesaw can be implemented at the electroweak scale in a natural way provided that the heavy neutrino singlets are quasi-Dirac particles. In such case, their contribution to light neutrino masses has the suppression of a small lepton number violating parameter, so that light neutrino masses can arise naturally even if the seesaw scale is low and the heavy neutrino mixing is large. We implement the same mechanism with fermionic triplets in type III seesaw, deriving the...

Source: http://arxiv.org/abs/0809.2096v3

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Sep 21, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra

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We investigate the LHC discovery potential for electroweak scale heavy neutrino singlets (seesaw I), scalar triplets (seesaw II) and fermion triplets (seesaw III). For seesaw I we consider a heavy Majorana neutrino coupling to the electron or muon. For seesaw II we concentrate on the likely scenario where the new scalars decay to two leptons. For seesaw III we restrict ourselves to heavy Majorana fermion triplets decaying to light leptons plus gauge or Higgs bosons, which are dominant except...

Source: http://arxiv.org/abs/0808.2468v2

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Sep 23, 2013
09/13

by
F. del Aguila; A. Culatti; R. Munoz-Tapia; M. Perez-Victoria

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We describe in detail the constrained procedure of differential renormalization and develop the techniques required for one-loop calculations. As an illustration we renormalize Scalar QED and show that the two-, three- and four-point Ward identities are automatically satisfied.

Source: http://arxiv.org/abs/hep-ph/9806451v1

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94

Sep 17, 2013
09/13

by
F. del Aguila; M. Zralek

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We review the propagation of light neutrinos in matter assuming that their mixing with heavy neutrinos is close to present experimental limits. The phenomenological implications of the non-unitarity of the light neutrino mixing matrix for neutrino oscillations are discussed. In particular we show that the resonance effect in neutrino propagation in matter persists, but for slightly modified values of the parameters and with the maximum reduced by a small amount proportional to the mixing...

Source: http://arxiv.org/abs/hep-ph/0207319v1

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35

Sep 19, 2013
09/13

by
F. del Aguila; M. Cvetic; P. Langacker

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The discovery of a new neutral gauge boson $Z'$ with a mass in the TeV region would allow for determination of gauge couplings of the $Z'$ to ordinary quarks and leptons in a model independent way. We show that these couplings in turn would allow us to determine the nature of the extended gauge structure. As a prime example we study the $E_6$ group. In this case two discrete constraints on experimentally determined couplings have to be satisfied. If so, the couplings would then uniquely...

Source: http://arxiv.org/abs/hep-ph/9501390v1

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31

Sep 18, 2013
09/13

by
F. del Aguila; J. Santiago

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We review the low energy limits on Kaluza-Klein excitations in orbifold models. New vector-like quarks, as well as new Z' gauge bosons, can be accommodated with masses observable at large colliders.

Source: http://arxiv.org/abs/hep-ph/0212205v1

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Sep 20, 2013
09/13

by
F. del Aguila; M. Zralek

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We count the number of CP breaking phases in models with $SU(2)_L\times U(1)_Y$ and $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ electroweak gauge groups and extended matter contents with some fermion masses vanishing and/or degenerate. Quarks and leptons, including Majorana neutrinos, are treated in a similar way. CP violation is characterized in the mass-eigenstate and in the weak-eigenstate bases. Necessary and sufficient conditions for CP conservation, invariant under weak basis redefinitions...

Source: http://arxiv.org/abs/hep-ph/9603223v1

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Sep 20, 2013
09/13

by
E. W. N. Glover; F. del Aguila; J. A. Aguilar--Saavedra; M. Beccaria; S. Bejar; A. Brandenburg; J. Fleischer; J. Guasch; T. Hahn; W. Hollik; S. Heinemeyer; S. Kraml; A. Leike; A. Lorca; W. Porod; S. Prelovsek; F. M. Renard; T. Riemann; C. Schappacher; Z. G. Si; J. Sola; P. Uwer; C. Verzegnassi; G. Weiglein; A. Werthenbach

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We review some recent developments in top quark production and decay at current and future colliders.

Source: http://arxiv.org/abs/hep-ph/0410110v3

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Sep 18, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra; J. de Blas; M. Perez-Victoria

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We review the present electroweak precision data constraints on the mediators of the three types of see-saw mechanisms. Except in the see-saw mechanism of type I, with the heavy neutrino singlets being mainly produced through their mixing with the Standard Model leptons, LHC will be able to discover or put limits on new scalar (see-saw of type II) and lepton (see-saw of type III) triplets near the TeV. If discovered, it may be possible in the simplest models to measure the light neutrino mass...

Source: http://arxiv.org/abs/0806.1023v1

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49

Sep 22, 2013
09/13

by
F. del Aguila; J. I. Illana; M. D. Jenkins

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The flavor sector of Little Higgs models based on product groups, notably the Littlest Higgs with T parity (LHT), has been extensively studied and some amount of fine tuning was found to be required to meet the experimental constraints. However, no such attention has been paid to other classes of models. Here we analyze the phenomenology of flavor mixing in the lepton sector of a simple group model, the Simplest Little Higgs (SLH). We obtain the Feynman rules of the SLH in the 't Hooft-Feynman...

Source: http://arxiv.org/abs/1101.2936v2

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Sep 19, 2013
09/13

by
F. del Aguila; Ll. Ametller; P. Talavera

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We discuss forward-backward charge asymmetries for lepton pair production in association with a large transverse momentum jet at hadron colliders. The measurement of the lepton charge asymmetry relative to the jet direction A_{FB}^j gives a new determination of the effective weak mixing angle sin^2{\theta_{eff}^{lept}(M_Z^2)} with in principle a statistical precision after cuts of \sim 10^{-3} (8 x 10^{-3}) at LHC (Tevatron), due to the large cross section of the process with initial gluons....

Source: http://arxiv.org/abs/hep-ph/0206160v2

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95

Jul 20, 2013
07/13

by
F. del Aguila; B. Alles; Ll. Ametller; A. Grau

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If a new $Z'$ is discovered with a mass $\sim 1 \ TeV$ at LHC/SSC, its (rare) decays into two charged leptons plus missing transverse energy will probe the $Z'$ coupling to the lepton doublet $(\nu,e)_L$ and to $W^+W^-$, allowing further discrimination among extended electroweak models.

Source: http://arxiv.org/abs/hep-ph/9206219v1

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Sep 18, 2013
09/13

by
F. del Aguila; J. Syska; M. Zralek

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We address the possible impact of New Physics on neutrino oscillation experiments. This can modify the neutrino production, propagation and/or detection, making the full cross section non-factorizable in general. Thus, for example, the neutrino flux may not be properly described assuming an unitary MNS matrix and/or neutrinos may propagate differently depending of their Dirac or Majorana character. Interestingly enough, present limits on New Physics still allow for observable effects at future...

Source: http://arxiv.org/abs/0809.2759v1

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Sep 23, 2013
09/13

by
F. del Aguila; J. de Blas

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We briefly review the limits on new interactions implied by electroweak precision data. Special attention is payed to the bounds on the Higgs boson mass. We also comment on the required cancellation among the new contributions to precisely measured electroweak observables in any Standard Model extension, if the new particles have to evade the indirect constraints on their couplings and masses but still remain at the LHC reach.

Source: http://arxiv.org/abs/1105.6103v1

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Sep 21, 2013
09/13

by
F. del Aguila; A. Culatti; R. Munoz-Tapia; M. Perez-Victoria

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Two applications of the method of differential renormalization to supersymmetric gauge theories are reviewed. The photon propagator in supersymmetric QED is renormalized at one loop and the first supergravity contributions to the anomalous magnetic moment of a charged lepton are obtained.

Source: http://arxiv.org/abs/hep-ph/9711474v2

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Sep 22, 2013
09/13

by
F. del Aguila; J. Syska; M. Zralek

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Dirac and Majorana neutrinos can be distinguished in relativistic neutrino oscillations if new right-handed interactions exist, due to their different propagation in matter. We review how these new interactions affect neutrino oscillation experiments and discuss the size of this eventually observable effect for different oscillation channels, baselines and neutrino energies.

Source: http://arxiv.org/abs/hep-ph/0702182v1

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Sep 19, 2013
09/13

by
F. del Aguila; A. Culatti; R. Munoz-Tapia; M. Perez-Victoria

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We present a procedure of differential renormalization at the one loop level which avoids introducing unnecessary renormalization constants and automatically preserves abelian gauge invariance. The amplitudes are expressed in terms of a basis of singular functions. The local terms appearing in the renormalization of these functions are determined by requiring consistency with the propagator equation. Previous results in abelian theories, with and without supersymmetry, are discussed in this...

Source: http://arxiv.org/abs/hep-th/9709067v2

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27

Sep 21, 2013
09/13

by
F. del Aguila; J. de Blas; P. Langacker; M. Perez-Victoria

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We study the possibility of relaxing the indirect limits on extra neutral vector bosons by their interplay with additional new particles. They can be systematically weakened, even below present direct bounds at colliders, by the addition of more vector bosons and/or scalars designed for this purpose. Otherwise, they appear to be robust.

Source: http://arxiv.org/abs/1104.5512v2

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Sep 17, 2013
09/13

by
F. del Aguila; J. A. Aguilar-Saavedra; M. Moretti; F. Piccinini; R. Pittau; M. Treccani

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We have implemented a code for Z' + n jets production in ALPGEN, with Z' decays into several final states, including l+ l- and t tbar. The MLM prescription is used for matching the matrix element with the parton shower, including in this way the leading soft and collinear corrections. In order to demonstrate its capabilities, we perform a combined analysis of Z' -> t tbar and Z' -> t tbar j production for a heavy leptophobic gauge boson. It is found that the effect of the extra jet cannot...

Source: http://arxiv.org/abs/0912.3799v1

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Sep 18, 2013
09/13

by
F. del Aguila; J. Santiago

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The Kaluza-Klein fermion excitations induce mixing between the Standard Model fermions and loss of universality. The flavour mixing not present in the Standard Model can be made to vanish aligning the Yukawa couplings and the Dirac masses of the heavy modes, but universality is only recovered when these masses go to infinity. This implies a bound on the lightest new heavy quark, M1 \~ 3-5 TeV, which together with the electroweak precision data limits will allow the Large Hadron Collider to...

Source: http://arxiv.org/abs/hep-ph/0008143v3

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Sep 22, 2013
09/13

by
F. del Aguila; J. Santiago

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Fermion mixing is conveniently described using the effective Lagrangian formalism. We apply this approach to study top mixing in models with an infinite tower of Kaluza-Klein fermion excitations. In the Randall-Sundrum background with a boundary Higgs and phenomenologically viable values of the model parameters, the only effect eventually observable is the loss of universality of the top couplings. Their deviation from the SM predictions can be up to 4 % if the five-dimensional Yukawa couplings...

Source: http://arxiv.org/abs/hep-ph/0011143v2

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72

Sep 22, 2013
09/13

by
M. Beneke; I. Efthymiopoulos; M. L. Mangano; J. Womersley; A. Ahmadov; G. Azuelos; U. Baur; A. Belyaev; E. L. Berger; W. Bernreuther; E. E. Boos; M. Bosman; A. Brandenburg; R. Brock; M. Buice; N. Cartiglia; F. Cerutti; A. Cheplakov; L. Chikovani; M. Cobal-Grassmann; G. Corcella; F. del Aguila; T. Djobava; J. Dodd; V. Drollinger; A. Dubak; S. Frixione; D. Froidevaux; B. Gonzalez Pineiro; Y. P. Gouz; D. Green; P. Grenier; S. Heinemeyer; W. Hollik; V. Ilyin; C. Kao; A. Kharchilava; R. Kinnunen; V....

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We review the prospects for studies of the top quark at the LHC.

Source: http://arxiv.org/abs/hep-ph/0003033v1

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39

Sep 18, 2013
09/13

by
F. del Aguila; M. Zrałek

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We study CP violation in the lepton sector in extended models with right-handed neutrinos, without and with left-right symmetry, and with arbitrary mass terms. We find the conditions which must be satisfied by the neutrino and charged lepton mass matrices for CP conservation. These constraints, which are independent of the choice of weak basis, are proven to be also sufficient in simple cases. This invariant formulation makes apparent the necessary requirements for CP violation, as well as the...

Source: http://arxiv.org/abs/hep-ph/9504228v1