From October 2009 onwards all seminars will be announced on this page.

Date

Lecturer

Title and Abstract

Files

5.10.2009

Amarjit Soni

Warped extra dimensions & the LHC

16.9.2009

Ilja Doršner

On d=6 proton decay operators

14.9.2009

Tsedenbaljir Enkhbat (ICTP Trieste)

SU(5) Yukawa unifications through SUSY threshold corrections

27.8. 2009

Ilja Doršner, Svjetlana Fajfer

Omejitve na leptokvarke iz fizike nizkih energij

30.7. 2009

Gorazd Cvetič (Univ. Tecnica Federico St. Maria, Valparaiso)

Analitična QCD

16.7. 2009

Veljko Dmitrasinovic (Vinca Institute)

A variational estimate of the Higgs mass
In view of the impending restart of LHC I offer a reminder of the 2.2 TeV calculation/prediction of the Higgs mass in the Standard Model based on the Gaussian functional variational approximation, by R. Ibanez-Meier, I. Stancu and P.M. Stevenson. Z.Phys. C70, 307 (1996). I show proofs of the gauge invariance (V.D., Nuov. Cim. 109A, 1187 (1996)) and of the unitarity and causality of this calculation (I. Nakamura and V.D., Nucl. Phys. A713, 133 (2003)).

9.7. 2009

Wei Liao (East China University of Science and Technology)

Equations and flavor transformation of neutrinos in supernova
We derive a series of moment equations describing the motion and flavor transformation of neutrinos in supernova. We find a particular series of moments of neutrino density matrix in supernova. The emission angle distribution of neutrinos is described by this series of moments. We expand the equation of neutrinos using these moments and obtain moment equations. We find that these moments have very good property of convergence and the infinite series of equations can be truncated to equations with a small set of moments. Using a small set of moment equations the required computational power is reduced by about two orders of magnitude compared to that in multi-angle simulation. The study on non-linear flavor transformation of neutrinos is substantially simplified using these equations. Two flavor system of neutrinos is also considered and new equations describing the flavor polarization vectors of neutrinos are found.

30.6. 2009

Manimala Mitra (Harish-Chandra Research Institute Allahabad, India)

Type-III Seesaw with 2HDM
Proof of neutrino masses and mixing from a series of outstanding experimental efforts have opened a window to physics beyond the standard model of particle physics. There must be some underlying theory which explains the very particular neutrino mass difference and mixing. It is well known that Seesaw mechanism has its success in explaining the smallness of neutrino mass. While many works have been recently done in the context of Type-III Seesaw which requires a fermionic triplet, we have concentrated on Type-III Seesaw in the presence of an additional Higgs doublet and on mu-tau symmetry. In this context we have studied the phenomenological predictions and the model signatures which Type-III Seesaw with 2HDM offers.

4.6. 2009

Jernej Fesel Kamnik (INFN Frascati)

Signatures of Heavy Vectors in Higgsless models
One or more heavy spin-1 fields may replace the Higgs boson in keeping perturbative unitarity up to a few TeV while at the same time account for the ElectroWeak Precision Tests. We study the Drell-Yan production of heavy vector and axial-vector states of generic Higgsless models at hadron colliders. We analyse in particular the l+l-, WZ, and three SM gauge boson final states. In the l+l- case we show how present Tevatron data restricts the allowed parameter space of these models. The two and three gauge boson final states (especially WZ, WWZ, and WZZ) are particularly interesting in view of the LHC, especially for light axial-vector masses, and could shed more light on the role of spin-1 resonances in the electroweak precision tests.

28.5. 2009

Jonathan Rocher (ULB-Brussels)

Challenges for hybrid inflation: SUSY GUTs, spectral index and initial
Now that CMB observational data increased in precision, the question of which (class of) models are the best candidates to realize inflation is particularly urging. Hybrid inflation is one of the three main classes of inflationary models and is considered very motivated among high energy physicists. After a quick review about hybrid inflation and the reasons why it is popular in the high energy community, I will discuss the phenomenology of these models and the challenges they have to face. I will first review some consequences of embedding it in SUSY GUTs : the difficulty to find an inflaton candidate and the constraints imposed by the formation of cosmic strings. I will then turn to two of its main problems: the blue spectral index in disagreement with WMAP5 and the space of initial conditions for inflation to be successful. I will show that the slow roll approximation should not always be trusted to study the model, and discuss what we learn from the exact dynamics in terms of spectral index and ways to realize hybrid inflation. We have used numerical resolution of the dynamics to understand and study the properties of the initial condition space available for successful inflation. I will show that both problems mentioned above can be avoided by considering superplanckian initial values for the fields and discuss the consequences for the models.

Based on arXiv:0809.4355, hep-ph/0406120, hep-ph/0308134 as well as work in progress : A. Mazumdar, J. Rocher, "Hybrid inflation: successes and challenges"

21.5. 2009

Bojan Golli

Uganke Roperjeve resonance

14.5. 2009

Eung Jin Chun (KIAS, Seul, Korea)

LFV and leptogenesis in Higgs exampt no-scale supergravity

7.5. 2009

Jan Eeg

Lamb-shift like effects in K decays

23. 4. 2009

Matej Pavsic

O posplositvi prostor-casa: teorija relativnosti v konfiguracijskem prostoru

17. 4. 2009

Jure Zupan (CERN, JSI)

General Minimal Flavor Violation

12. 3. 2009

Ho-Ung Yee (ICTP)

Holographic Monopole Catalysis of Baryon Decay

26. 2. 2009

Jure Drobnak

Kratek pregled fizike top kvarka in predstavitev nase analize razpada t --> c l+l-

19. 2. 2009

Abdesslam Arhrib (Tanger University, Morocco)

Charged Higgs Phenomenology

29. 1. 2009

Ivica Picek (University of Zagreb)

New TeV-scale Quark in Rare K and B Decays
It is conceivable that possible new quark states can be out of the direct LHC production reach, and that one could infer on them from their virtual loop effects. We introduce a secondary top state allowed by the existing electroweak precision tests. This state satisfies the requirements of small CKM unitarity violation and minimal flavour violation, and we examine its effects on selected rare K and B decays. It turns out that such rather heavy extra top has the best chance to be recovered via an increase in B_s -> mu^+ mu^- decay rate measured at the LHC.

22. 1. 2009

Lorenzo Calibbi (SISSA, Trieste)

Gauge coupling unification with magic fields
We consider field sets that do not form complete SU(5) multiplets, but exactly preserve the one-loop MSSM prediction for alpha_3(M_Z) independently of the value of their mass. The unification scale is in general affected by such new fields and can be raised to larger values. These ``magic'' fields represent a useful tool in GUT model building: they can be used to fix gauge coupling unification in two-step breakings of the unified group, to suppress large KK thresholds in models with extra dimensions, or they can be interpreted as messengers of supersymmetry breaking in GMSB models.

15. 1. 2009

Anze Slosar (Univ. of California, Berkeley)

Minimalna inflacija in njeni eksperimentalni testi
V predavnju bom poskusal na preprost nacin motivirat osnovne rezultate inflacije in 4 osnovne eksperimentalne teste: spekter moci primordialnih fluktuacij, isokurvature fluktuacije, B-nacin prasevanja in negaussovska porazdelitev fluktuacij.