Jeudi 29 Juillet 2010 à 16h, salle 114
Pablo Roig (LPT Orsay) : A precise determination of the eta_c
mass and width from radiative J/Psi decays
Motivated by two recent analysis by the CLEO and KEDR
collaborations of the eta_C line shape in radiative J/Psi decays, we have studied the problem within an EFT approach provided by potential-NRQCD (pNRQCD) that exploits : the non-relativistic nature of the problem, the weak-coupling regime where these states lie and the multiple expansion in the photon energy in a consistent framework. Relativistic corrections to
the lowest order result are also included.
We compare our results for the eta_c mass and width to those found by CLEO and KEDR and comment on the related uncertainties and issues.
Mercredi 21 Juillet 2010 à 16h, salle 114
Igor Bogolubsky (JINR Dubna) : Towards the continuum limit of the lattice Landau-gauge gluon and ghost propagators
Considerable efforts have been devoted during the last decade to
exploring QCD’s elementary two-point functions using the framework of lattice QCD. Thereby, much attention has been paid to the gluon and ghost propagators in Landau gauge whose low-momentum behavior has been explored using relatively coarse lattices to reach momenta as low as possible. To ultimately confront such lattice results with corresponding predictions from continuum functional theory, the extrapolation to the continuum limit has to be under control, however. Also, the influence of the Gribov ambiguity needs to be understood, in particular as there are strong indications that this ambiguity has a big impact on these
propagators at low momenta.
To further clarify this still actively debated issue we have launched a large scale lattice study of this problem in SU(2) gluodynamics, paying special attention to the continuum limit of the gluon and ghost propagators and the associated coupling at a fixed physical volume.
Jeudi 3 Juin 2010 à 11h, salle 114 (HORAIRE INHABITUEL)
Julien Serreau (APC) : 2PI functional techniques for gauge theories
Two-particle-irreducible (2PI) techniques provide a powerful
resummation tool in quantum field theory, of interest for the description of quantum fields at high temperature, or of far-from-equilibrium dynamics. We discuss the formulation of 2PI techniques for gauge theories, with particular emphasis on the key issues of symmetries and renormalization.
Mardi 1er Juin 2010 à 16h, salle 114
Nils Offen (Université de Regensburg) : On one-loop renormalization of heavy-light light-ray operators
In light-cone gauge the renormalization at one loop of light-ray operators is governed by 2-particle kernels. Based on work done by Bukhvostov, Frolov, Lipatov, Kuraev and Braun, Manashow, Rohrwild in the light-light case this property is used to generalize known results for the one-loop renormalization of heavy-light operators. Comparing to results for light-light operators, we tentatively point out similarities and take first steps towards an understanding of the mixing pattern of different heavy-light light-ray operators.
Jeudi 27 Mai 2010 à 16h, salle 114
Slava Rychkov (LPT ENS et Université Paris VI) : Gravitational scattering at transplanckian energies
Suppose that a TeV-scale gravity scenario, like in Large Extra Dimensions, is realized in Nature, so that LHC protons will collide at CM energies exceeding the Planck scale. What shall we see ? In this talk we will discuss the common lore and continuing theoretical work trying to clarify this question.
Jeudi 20 Mai 2010 à 16h, salle 114
Mauro Anselmino (Universite de Turin) :
Spin effects at high energy and the nucleon structure
Several surprising spin effects have been and keep being observed and measured in the last years in several inclusive processes at high energies. Their interpretation and description can be related to the intrinsic motion of quarks, thus leading to a possible 3-dimensional exploration of the partonic structure of protons and neutrons.
Jeudi 29 Avril 2010 à 16h, salle 114
Dru Renner (DESY) : Hadronic contribution to g-2 from lattice QCD
The hadronic contributions to the anomalous magnetic moment of the
muon are an interesting challenge for lattice QCD calculations,
especially given a persistent discrepancy between theory and
experiment. We have calculated the leading order hadronic contribution for pion masses from 600
MeV to 270 MeV using dynamical twisted mass fermions. This observable receives a significant
contribution from two pion states, in particular the rho resonance. Time permitting, I’ll show
some results from our current efforts to analyze pion-pion scattering on
the lattice.
Jeudi 22 Avril 2010 à 16h, salle 114
Pasquale di Bari (Université de Southampton) : N_2-dominated leptogenesis
In my talk I will discuss a scenario of minimal leptogenesis (thermal + type I seesaw
mechanism) that
is interesting because potentially testable just at future low energy neutrino experiments.
In the last years it become clear that a reliable calculation of the final asymmetry in
leptogenesis has in general to take into account the contribution produced from the heavier
RH neutrino decays. In particular
the contribution from the next-to-lightest RH neutrinos (the "N_2" neutrinos) decays can be
the dominant source when the RH neutrino
mass spectrum exhibits a strong hierarchy and the lightest RH neutrino N_1 is sufficiently
light to give a negligible contribution to the final asymmetry.
Interestingly, this scenario can be motivated within grand unified theories. In this case
further restrictions can be imposed on
the seesaw parameters such that the final asymmetry can be expressed just in terms of the
low energy parameters.
Furthermore, imposing successful leptogenesis could potentially yield predictions on the low
energy neutrino parameters.
I will show how recently studied effects, flavour coupling and so called phantom terms,
can remarkably influence the final result and have therefore to be taken into account.
Jeudi 15 Avril 2010 à 16h, salle 114
Kirill Semenov (LPT et CPHT Ecole Polytechnique) : Pion-nucleon transition distribution amplitudes : conformal PW expansion v.s. spectral representation
Pion-nucleon transition distribution amplitudes are the recently
proposed non-perturbative objects which arise
e.g. in the description of exclusive production of baryons off nucleons on the base of QCD factorization.
I am going to discuss the possible approaches to the problem
of suggesting of phenomenological parametrizations for pion-nucleon
TDAs.
Jeudi 8 Avril 2010 à 16h, salle 114
Domenec Espriu (CERN et Université de Barcelone) : Using high energy cosmic rays to detect the axion halo
We investigate the propagation of a charged particle in a spatially
constant, but time dependent, pseudoscalar background. Physically this pseudoscalar background could be provided by a relic axion density. The
background leads to an explicit breaking of Lorentz invariance ; as a consequence the process p-> p gamma is possible and the background acts as a
shield against extremely energetic cosmic rays, an effect somewhat similar to the GZK cut-off effect. The effect is model independent and can be computed exactly. The hypothetical detection of the photons radiated via
this mechanism would provide an indirect way of verifying the cosmological
relevance of axions.
Mardi 6 Avril 2010 à 16h30, salle 114
Javier Virto (Université de Rome) : Flavor Physics in the MSSM
Flavor changing processes involving mesons have been used for over
15 years to constrain the soft SUSY breaking sector of the MSSM. The fact that the flavor structure of this sector is highly non-generic is called the
SUSY flavor problem. Most of the phenomenological analyses on the general MSSM have therefore assumed that the spectrum is almost aligned or degenerate. I will review the calculation of the effective low energy theory for quark flavor changing processes in the MSSM, and the related
phenomenology, going beyond the degenerate squark approximation.
Vendredi 26 Mars 2010 à 15h30, Amphi 1
Swarup Kumar Majee (Université de Louvain) : Neutrino mass and leptogenesis in a SUSY SO(10) model
The smallness of the neutrino mass can be explained by different type of seesaw mechanism. Type-I seesaw is realised with a heavy right handed Majorana neutrino, natrual element in SO(10) GUT model, which can also generate the observed
lepton asymmetry through it’s decay. On the other hand low scale supersymmetry not only helps to explain the wide disparity between the weak and GUT scales but also leads to a unification of gauge couplings at high energies. The mass scale of this right-handed
neutrino, thus, constrained by several aspects of physics. In our work, introducing an SO(10) singlet lepton, we find a novel way to accommodate the observed neutrino masses and mixings as well as generate the desired lepton asymmetry.
Jeudi 18 Mars 2010 à 16h30, salle 114
Alessio Notari (CERN et Université de Heidelberg) : Inflation from Phase Transitions in Scalar-Tensor theories and an
Approach to the Hierarchy Problem
Inflation with tunneling from a false to a true vacuum is viable in
the presence of a non-minimally coupled scalar field. This has precise interesting predictions on cosmological scalar and tensor fluctuations in the CMB. Moreover we predict a spectrum of gravity waves produced at reheating with large amplitude.
As a by-product the additional field also sets dynamically the value of the Planck mass, which can be exponentially large. Therefore along with Inflation we also suggest a dynamical explanation for why gravity is so weak today. In this case the spectrum of gravity waves is peaked at 0.1 mHz and thus detectable by the planned space inteferometer LISA. Finally we discuss possible ways of making the additional scalar compatible with late-time constraints.
Mardi 16 Mars 2010 à 16h30, salle 114
David Greynat (Université de Barcelone) : Mellin-Barnes representation and calculations in Quantum Field Theory
In a first part of my talk, I will show how the Mellin-Barnes representation of Feynman diagrams with one scale (i.e. one ratio of masses and/or momenta), when combined with the converse mapping theorem, allows the simplification of the analytic evaluation, to an arbitrary order, of their asymptotic expansions in powers and logs of this scale. In a second part, I will extend this method to Feynman diagrams containing several scales. For this, we will use multidimensional complex analysis and especially multidimensional residues theory. This very general technique can be applied
to different domains. I will illustrate it by evaluating analytically a specific class of 5-loop QED contributions to the anomalous magnetic moment of the muon, involving the masses of the electron, muon and tau and some other integrals involved in the calculation of the hadronic contributions to the g-2. At last, in a third part, I will show that the Mellin-Barnes representation may also deal with non-perturbative effects, although its
kernel is of perturbative type. Mixing Mellin-Barnes representation, inverse factorial expansions and Borel resummation, we will see that it is possible
to rewrite, in terms of non-perturbative series, the tail of the (divergent) formal power series which constitutes the perturbative expansion of an arbitrary N-point function for the simple case of zero-dimensional $phi^4$ field theory. The perturbative results will then give birth to hyperasymptotic expansions.
Vendredi 12 Mars 2010 à 16h30, salle 114
Duc Ninh LE (Max Planck Institute) : Electroweak radiative corrections at colliders.
In this talk I will discuss the electroweak radiative corrections to WWZ and ZZZ production
at the linear collider, and also bbH production at the LHC.
In so doing I will explain in some detail how to do an one-loop multi-leg calculation.
The topic of Landau singularity and its phenomenological consequences in bbH production at the
LHC will also be considered.
Jeudi 11 Mars 2010 à 16h30, salle 114
Emilie Passemar (Université de Valence) : Study of eta —> 3 pi decays with a dispersive approach
Recently, an important effort has been devoted at KLOE, MAMI and COSY to precisely measure the eta —> 3
pi decays. These new measurements require to revisit the theoretical analyses of these decays. In this
talk, we will present a new analysis of the eta —> 3 pi decay amplitude relying on dispersive methods.
Using analyticity and unitarity, the amplitude is determined up to subtraction constants which are then
fixed by a combined matching to the experimental measurements and to the calculations of chiral
perturbation theory. This approach is particularly interesting, since it allows to take into account the
pi pi rescattering effects, which are known to be significant in this channel.
We will show how the study of this decay allows to extract a fundamental parameter of the Standard
Model, namely the quark mass ratio
(m_d^2-m_u^2)/(m_s^2-\hatm^2) with a good precision.
Jeudi 4 Mars 2010 à 16h30, salle 114
Giovanni Chirilli (LPT et CPHT Ecole Polytechnique) : High-Energy Amplitudes in Gauge Theories at next to leading order
At high-energy (Regge limit) the T product of two currents can be expanded in terms of coefficient functions (impact factors) and matrix elements of "composite color dipoles" made of Wilson line operators with rapidity cutoff preserving conformal invariance. The behavior of the amplitude in gauge theories can then be reformulated in terms of Wilson-line operators, and the evolution at leading order is governed by the non-linear Balitsky-Kovchegov (BK) equation.
In order to see if the BK equation is relevant for existing or future deep inelastic scattering (DIS) accelerators (like Electron Ion Collider or Large Hadron electron Collider) one needs to know the NLO corections. In addition, the NLO corrections define the scale of the running-coupling constant in the BK equation and therefore determine the magnitude of the leading-order cross section. Using the high-energy OPE, we find the next-to-leading order (NLO) correction to the BK equation and calculate the impact factor for virtual photons in deep inelastic scattering.
Mardi 2 Mars 2010 à 16h30, salle 114
Jean-Philippe Lansberg (CPHT Ecole Polytechnique) : Looking at hadrons in the backward direction with hard photons : the Transition Distribution Amplitudes
I will discuss the potentialities offered by the study of backward exclusive processes in the
scaling regime, such as backward DVCS, backward electroproduction of a meson. I shall first
introduce the concept of Transition Distribution Amplitudes (TDAs) by underlining some
similarities and differences compared to Generalised Parton Distributions (GPDs). As a first
illustration, I will discuss the simple case of gamma* gamma -> rho pi at small t, for which we
can extend models used for GPDs. I will discuss also the possibility to study DVCS on a
virtual-pion target. Finally, I shall focus on the baryonic transitions such as p -> pi, which
appear in backward electroproduction of a meson at JLab and Compass as well as in the production
of a hard dilepton with a pion in exclusive antiproton-proton annihilations at GSI. In the latter
case, I will discuss our first estimate of some cross sections that will be measured soon and our
plans to study the heavy quark content in the proton.
Jeudi 25 Février 2010 à 16h30, salle 114
Stefano Actis (Paul Scherrer Institut) : NLO electroweak corrections to Higgs production in gluon-gluon fusion
The production of the Higgs boson via gluon fusion is a key processes at the LHC and several classes of higher order corrections have been computed in the last few years.
In this seminar I will focus on the evaluation of the two-loop electroweak corrections in the context of the Standard Model, comparing results obtained through different schemes
for dealing with unstable particles and showing the numerical relevance for collider physics.
Jeudi 11 Février 2010 à 16h30, salle 114
Adam Falkowski (Rutgers University) : Hidden Higgs
I will talk about a class of models that allow the Higgs boson
to be much lighter than the naive LEP limit of 114.4 GeV. This is possible because the Higgs searches at LEP are less sensitive to Higgs decaying into multiparticle final states. Recent theoretical ideas include models where the Higgs decays into (more than two) hadronic jets, or into lepton jets, which allow the Higgs to be as light as 90-100 GeV without violating any experimental constraints. I will discuss the prospects to discover such Higgs at Tevatron and the LHC, as well as in the old LEP data.
Jeudi 4 Février 2010 à 16h30, salle 114
Pablo Roig-Garces (LPT) : Recent improvements in our understanding of Tau decays
A convenient framework to study hadron decays of the tau is that of
Resonance Chiral Theory, an Effective Field Theory based on the following properties of QCD : its approximate chiral limit at low-energies, its large N_C limit and the known asymptotic behaviour of its form factors. We will present some ongoing developments in the decays to pi/K gamma nu and to eta pi pi nu and check the consistency with previous results in other three meson decay modes. Our results are being used to improve the description of the hadronization of QCD currents in hadron tau decays (TAUOLA) and the hadron cross section e^+e^- at low energies.
Jeudi 21 Janvier 2010 à 16h30, salle 114
Nazario Tantalo (Université de Rome) : A lattice study of semileptonic decays of B mesons into D^(*) mesons
I will discuss the results of a quenched lattice calculation of
the decay rates of the semileptonic processes B—>D^(*) l nu at non
vanishing momentum transfer. In particular, I will describe the
strategies adopted to handle with heavy-light mesons on the lattice
and to calculate three-point correlation functions at non-vanishing
spatial momenta with reasonable accuracy. Finally, I will discuss the
phenomenological relevance of these results in the extraction of the
CKM matrix element |V_cb| from experimental data and some future
developments.
Jeudi 14 Janvier 2010 à 16h30, salle 114
Séminaire à 2 voix : Mounir El Beiyad et Charles Bouchart (LPT)
1) Mounir El Beiyad : Structure des Hadrons dans les Réactions Exclusives
Les réactions exclusives en Chromodynamique Quantique permettent de
déterminer les grandeurs des différentes caractéristiques de la structure
des Hadrons. Cette étude théorique a permis de mettre en évidence notamment
les Distributions de Partons Généralisées (GPD) et les Distributions
d’Amplitude Généralisées (GDA) et leur intérêt phénoménologique. Je
présenterai donc ces différentes notions, en mettant en avant la
possibilité, via un processus physique particulier, d’extraire des
informations sur la structure en spin du proton.
2) Charles Bouchart : Phénoménologie du Higgs dans le modèle de Randall-Sundrum
Depuis une dizaine d’années, de nombreux modèles à dimension(s)
supplémentaire(s) ont fait leur apparition, proposant des alternatives
intéressantes à la SuperSymétrie pour tenter de résoudre le problème de
hiérarchie. Je commencerai par présenter l’un de ces modèles, introduit
par Lisa Randall et Raman Sandrum, dans lequel s’inscrivent mes travaux de
thèse. Puis, j’introduirai la phénoménologie du Higgs dans ce modèle, ses
différents couplages aux particules du modèle standard, et le rôle des
mesures de précisions électrofaibles pour contraindre le modèle. Enfin, je
concluerai sur les perspectives qu’offrent ce modèle.
Jeudi 7 Janvier 2010 à 16h30, salle 114
Cyrille Marquet (IPhT CEA/Saclay) : Forward particle production in dA collisions 
Single particle observables (inclusive spectra and nuclear modification
factors) in d-Au collisions at RHIC are often quoted as evidence for the
Color Glass Condensate (CGC), condisering the suppressed production at
forward rapidities. Indeed, these kinematics probe partons in the nucleus
that have a small fraction of momentum $x,$ and it is natural to expect
non-linear QCD to play a role. Following the recent d-Au run at RHIC, new
measurements provide further tests of the CGC picture. In particular,
di-hadron correlations in azimuthal angle reveal the disappearance of the
away-side peak at forward rapidities, in quantitative agreement with CGC
predictions made earlier. I will review the theory and phenomenology of this
"jet quenching phenomenon" in d-Au collisions, and argue that it completes
the evidence that a nucleus probed at small-x is described by a CGC.
SOUTENANCE DE THESE
Vendredi 11 Décembre à 11h, salle 114
Emmanuel Chang (LPT Orsay) : QCD sur réseaux et les propriétés des mésons lourds-légers.
Les distributions radiales dans les mésons lourds-légers et le mélange B^0-\bar B^0 dans la limite statique
La phénoménologie des mésons lourds-légers est étudiée à l’aide de
simulations de QCD sur réseau. Le présent travail est particulièrement
centré sur la dynamique du quark léger dans des systèmes lourds-légers
lorsque le quark lourd est infiniment massif. La différence de masse entre
l’état fondamental et les états excités est étudiée grâce à des données
réseau "unquenched" possédant N_f=2 quarks légers dynamiques. Une
très haute précision des résultats sur réseau pour les couplages d’un
pion mou est obtenue en améliorant plusieurs aspects des précédents calculs sur
réseau de ces couplages. De plus, ce travail propose une nouvelle méthode
permettant de déterminer pour la première fois l’émission d’un pion au
cours de la transition entre l’état fondamental et le premier état
excité d’un méson lourd-léger. Ces couplages constituent des ingrédients
nécessaires pour la description des mésons lourds-légers à l’aide
d’une théorie effective connue sous le nom de Théorie Chirale des Perturbations
pour les Mésons Lourds. Ils sont aussi essentiels pour l’extrapolation
chirale des résultats obtenus sur réseau en matière de phénoménologie de la physique du B.
Nous portons un soin particulier à l’amélioration de la méthode employée
pour calculer le propagateur du quark lourd statique sur réseau en
utilisant les techniques de mise en bloc hyper-cubique (HYP). Nous
procédons ensuite à une étude détaillée des éléments de
matrice hadronique de tous les opérateurs \Delta B=2 à quatre quarks conservant la parité qui
entrent dans la description théorique de l’amplitude du mélange
B^0-\bar B^0 dans le Modèle Standard ainsi que dans ses extensions supersymétriques.
C’est la première étude de ce genre avec des lignes de Wilson avec
mise en bloc HYP, avec un bénéfice supplémentaire : le mélange spurieux
d’opérateurs calculés sur réseau est nettement réduit par rapport aux
travaux antérieurs sur le sujet. La renormalisation et le matching de la
Théorie Effective de Quark Lourd sur réseau et de la QCD dans le continu
est effectué en utilisant la théorie de perturbations boostée. Nous
fournissons également une brève discussion de l’impact de nos résultats
sur la phénoménolgie du méson B.
Jeudi 3 Décembre à 16h30, salle 114
Mathieu Segond (Leipzig) : Small-x resummation in collinear factorization
The resummation of the small-x corrections to hard
scattering amplitudes in pQCD by collinear factorisation
method is reconsidered and the resulting correction factor is derived in leading logarithm approximation. Our result is compared and disagrees with the corresponding expression by Catani and Hautmann (1994).
The significance of the correction is demonstrated in the examples of the longitudinal structure function and of exclusive vector meson electroproduction.
The formulation covers the channels of non-vanishing conformal spin $n$ paving the way for new applications.
SOUTENANCE DE THESE
Vendredi 27 Novembre à 11h, Amphi I
Benjamin Haas (LPT Orsay) : QCD sur réseau et physique du charme
We will present the results obtained on precision
calculations of some charm quark properties relevant for
phenomenology. As every quark, the charm quark interacts through the
electroweak interaction and the strong interaction. At present,
solving the strong interactions analytically is impossible. To
compute the physical properties, we used a well-defined numerical and
model-independent approach namely Lattice QCD. We used two different
realizations of the Wilson quarks, namely the Wilson—Clover quark and
the twisted mass quarks. When correctly tuned, both offer an O(a)
improvement which is essential in studying the charm physics on the
lattice. We worked out new techniques that reduce the
systematic error so that a 1%
accuracy can be achieved by only increasing the statistics. Moreover,
we worked with Nf=2 quarks in the
sea so that the main contribution to the quantum fluctuations of the
vacuum has correctly been taken into account. The u/d quarks are always
degenerated with the sea quarks so that the theory does not suffer from
the breaking of unitarity that arises in quenched theories.
We studied the properties of the D*-meson decays in a comprehensive
way which has never been done before.
Our unquenched calculations of
the coupling of D*-meson to the D-meson and the pion is an essential
update of previous calculations. Among the new techniques we used, the
twisted boundary conditions allowed us to
control the momentum on the lattice in very fine way. We used
this technique to devise the first calculation of the coupling of
the D*-meson do the D-meson and the soft photon. We emphasize that from our
computation we can confirm the compatibility of the experiment with the
theory without making any assumption, and emphasize that our
calculation should be improved in the future by just increasing the
statistics.
We then significantly improved the calculations of the properties of
the D-meson decays. We extracted the pseudoscalar and vector decay
constants from
simulations with Wilson-Clover quarks and twisted mass quarks. We also
studied the coupling of the vector meson to the tensor density which
can be helpful for constraining the physics beyond the Standard
Model. Finally, we computed the vector and scalar form
factors of the semileptonic decay of the D -> pi l nu
decay. We also computed the tensor form factor that is interesting for
studies of the new physics.
We finally combined all our results for studying the shape of the
vector form factor and compare it with Vector Meson Dominance.
SOUTENANCE DE THESE
Vendredi 20 Novembre à 10h30, salle 114
Charles-Christophe Jean-Louis (LPT Orsay) : Secteurs de Higgs et neutrinos dans le NMSSM
Le NMSSM est une extension supersymétrique du Modèle Standard très
bien motivée du point de vue expérimental et du point de vue
théorique. En effet, ce modèle apporte une solution au problème mu du
MSSM tout en étant moins contraint que ce dernier expérimentalement.
Après un bref rappel des modèles supersymétriques les plus utilisés,
nous discuterons la brisure de la supersymétrie par médiation de jauge
dans le NMSSM, nous verrons ensuite que la brisure de R-parité permet
de générer des masses pour les neutrinos à l’ordre de l’arbre tout en
conservant un candidat viable pour la matière noire. Finalement, une
possibilité de contraindre la supersymétrie via l’observation des
neutrinos émis lors d’une supernova est analysée.
Jeudi 19 Novembre à 16h30, salle 114
Fu-Sin Lin (Université de Bruxelles) : Inert Multiplet Dark Matter and Direct Detection experiments
The addition of a new, odd under some parity symmetry and weakly
interacting scalar multiplet provides a simple yet rich extension of the
Standard
Model which can account for Dark Matter. Direct detection experiments
provide
strong constraints on such models. When the additional multiplet is a
doublet, two
solutions provide a simultaneous fit of the DAMA modulation data and all
the other
constraints. Either the DM is light (mDM 10 GeV) and scatters
elastically with a
nucleus, with Higgs portal type scalar interactions. Either the DM is
heavy (mDM 1
to 10 TeV) and scatters inelastically on nuclei, through a Z boson. For
higher
multiplets, at the renormalizable level, only multiplets with zero
hypercharge are
allowed. For real multiplets, the predicted signal is below current limits
but above
future ton sized experiments projections. If non renormalizable operators are
allowed, suppressed by some cut-off scale, small mass splittings as needed
for the
inelastic solution of DAMA may naturally appear and rescue some models
with non zero
hypercharge.
Vendredi 11 Septembre à 11h, salle 100, LAL, Bâtiment 208
Séminaire LAL / LPT
N. Nikitin (Moscow State University) : Theoretical overview of the rare B-decays with leptons in the final state
In current talk we will present the theoretical overview for rare
semileptonic and rare radiative leptonic
decays. Additionaly we will compare the theoretical predictions with the
experimental data
and will consider the applications of the theoretical approaches to the
Monte-Carlo Generators.
Accès / Find us
Séminaires Particules 2009-2010