| MONDAY 10th |
| THEORY |
| 17:00-17:15 |
Ennio Salvioni (Padova U.): Minimal Z' models and the early LHC
We consider a class of minimal extensions of the Standard Model with
an extra massive neutral gauge boson Z'. They include both a
family-universal model, where the extra U(1) is associated with (B-L),
and non-universal models where the Z' is coupled to a non-trivial
linear combination of B and the lepton flavors. We discuss the
interplay between electroweak precision tests and direct searches at
the Tevatron, to assess the discovery potential of the early LHC.
|
| 17:15-17:30 |
Jure Drobnak (Jozef Stefan Institute - Slovenia): FCNC top quark decays
We study flavor changing neutral currents decays of the top quark,
t->c Z and t->c gamma. These decays are highly suppressed in the
standard model. Numerous extensions of the standard model however,
still allow significant enhancement of the branching ratios for such
processes. Using most general model independent Lagrangian approach
we analyze the aforementioned decays and try to find observables that
could help to discriminate among variety of new physics scenarios. We
also present a full next to leading order QCD analysis and the impact
it may have on the observability of these FCNC processes.
|
| 17:30-17:45 |
Roberto Barcelo (Granada U.): Extra Higgs bosons in $t \bar t$ production at the LHC
The top quark has a large Yukawa coupling with the Higgs boson. In the
usual extensions of the standard model the Higgs sector includes extra
scalars, which also tend to couple strongly with the top quark. Unlike
the Higgs, these fields have a natural mass above 2m_t, so they could
introduce anomalies in ttbar production at the LHC. W e study their
effect on the ttbar invariant mass distribution at sqrt{s}=7 TeV. W e
focus on the bosons (H,A) of the minimal SUSY model and on the scalar
field (r) associated to the new scale f in Little Higgs (LH) models. W
e show that in all cases the interference with the standard amplitude
dominates over the narrow-width contribution. As a consequence, the
mass difference between H and A or the contribution of an extra
T-quark loop in LH models become important effects in order to
determine if these fields are observable there. W e find that a 1
fb^{-1} luminosity could probe the region tan beta \le 3 of SUSY and
v/(\sqrt{2}f) \ge 0.3 in LH models.
|
| 17:45-18:00 |
Paolo Lodone (Scuola Normale Superiore - Pisa): Increasing the Higgs mass bound of the Minimal Supersymmetric
Standard Model
In the MSSM the Higgs boson mass at tree level cannot exceed the Z
boson mass. One could then ask himself the following question: should
we throw away Supersymmetry if we don't see the Higgs boson at the
LHC? To answer this question it makes sense to consider extensions of
the MSSM in which the Higgs boson can be relatively heavier. An
additional motivation to look in this direction comes from flavour
physics, since a heavier Higgs boson would relax the naturalness
bounds on the masses of the sfermions of the first two generations,
allowing them to be heavier and thus in better agreement with the
experimental absence of any signal so far. I will consider three
possibile models, and discuss their implications.
|
| EXPERIMENTAL
|
| 18:00-18:15 |
Ilaria Besana (Milano U.): Study of W+jets background to top quark pair production cross section
in ATLAS at the LHC.
The measurement of top quark pair production cross section in p-p
collisions at a center of mass energy of 10 and 7 TeV is one of the
first measurements that will be made by ATLAS at the LHC. The most
promising channel is the semileptonic final state, where one of the
top decays into a W decaying into hadrons and the other top into a W
decaying leptonically. The main background to this channel comes from
the direct production of W bosons in association with four hadronic
jets. Monte Carlo predictions for the rate of this background have
large uncertainties. However it will be important to know it with
precision in order to make an accurate measurement of the top quark
pair production cross section. I will show how we can use data in
order to give a precise estimation of W+jets contribution to the
selected sample of top quark pair candidates, in order to minimize the
uncertainties from Monte Carlo.
|
| 18:15-18:30 |
Giordano Cattani (Tor Vergata U.): Underlying event studies in first data collected by the ATLAS experiment
On November 2009 LHC started to deliver the first collisions at a
centre of mass energy of 900 GeV. About 1 million of Minimum Bias
events have been collected since then by the ATLAS experiment. One of
the first measurement is the understanding of the Underlying event to
the hard scattering process. One way to study the Underlying event is
to use the topological structure of hadron-hadron
collisions. Considering the DeltaPhi distribution of the density of
charged particles relative to the direction of the leading track/jet
one could apply the Fourier Transformation technique to show various
scales and structures arising as the energy of the leading track
increases. In this talk will be shown very preliminary results from
this technique applied on this first data.
|
| 18:30-18:45 |
Francesco Guescini (Tor Vergata U. and Geneva U.): Minimum bias analysis at the ATLAS experiment
In December 2009 the ATLAS experiment has collected data at an energy
in the center of mass of 900 GeV. A description of the minimum bias
analysis that has been carried out is presented, including the study
of the charged particle density in I. and pT and the comparison with
Monte Carlo simulations. Particular attention is given to the study of
beam background and tracking reconstruction efficiency of the ATLAS
Inner Detector.
|
| 18:45:19:00 |
Viacheslav V. Kaminskiy (BINP, Novosibirsk): Measurement of beam energy using inverse Compton scattering
Head-on scattering of the radiation from the monochromatic carbon
dioxide laser with the electron beam of the VEPP-4M collider provides
backscattered photons. Their energy spectrum is measured by the HPGe
detector to obtain an absolute value of the maximal possible energy of
a backscattered photon. Photons with such an energy form a sharp
high-energy edge in the spectrum allowing a measurement of the average
energy of an electron beam with an accuracy dE/E ~ 30 ppm.
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|
|
|
THURSDAY 13th
|
| EXPERIMENTAL |
| 17:00-17:15 |
Roberto Iuppa (Tor Vergata U.): Monitoring the Mrk421 flaring activity by the ARGO-YBJ
experiment
ARGO-YBJ is an extensive air shower detector exploiting the full
coverage approach at high altitude (4300 m a.s.l.), mainly devoted to
gamma-ray astronomy in the TeV energy range. Among the most important
sources detected by ARGO-YBJ, Mrk421 is a blazar close to Earth
(redshift: z=0.03), intensely studied because of its highly varying
flaring activity. During the last four years, three major flaring
periods have been observed by ARGO-YBJ, in July 2006, in June 2008 and
in February 2010. The flares show different spectral features, mostly
as far as the relation between the X-ray and the gamma emissions is
concerned. The status of the observation of Mrk421 is discussed.
|
| 17:15-17:30 |
Izabela Balwierz (Krakow U.): Study of the decoherence of entangled kaons by the interaction with
thermal photons
The KLOE-2 detector is a powerful tool to study the temporal evolution
of quantum entangled pairs of kaons. The accuracy of such studies may
in principle be limited by the interaction of neutral kaons with
thermal photons present inside the detector. Therefore, it is crucial
to estimate the probability of this effect and its influnence on the
interference patterns. In the talk I will introduce the phenomenology
of the interaction of photons with neutral kaons and will present and
discuss the obtained quantitative results.
|
| 17:30-17:45 |
Tomasz Twarog: Investigations of the time interval distributions between the decays
of quantum entangled neutral kaons
One of the physics issues to be investigated in KLOE-2 experiment is
the time evolution of quantum entangled neutral kaons. Studies of
kaons' decay times distributions enable us to test CPT symmetry and
quantum mechanics (QM). In this presentation it is shown how these
distributions can be obtained on the basis of QM. It is also discussed
how CPT and QM violations can manifest themselves in the interference
patterns of entangled kaons which will be measured by means of the
KLOE-2 detector setup.
|
|
THEORY
|
| 17:45-18:00 |
Rodrigo Alonso (UAM - Madrid): MINSIS and Minimal Flavour Violation
We explore the reach of future near detectors sensitive to tau appear-
ance, such as the recently proposed MINSIS project, to further
constrain neutrino mass models. A neutrino Minimal Flavour Violation
model will be analyzed in detail, taking into account as well future
MEG detection prospects.
|
| 18:00-18:15 |
Daniel Hernandez (UAM - Madrid): The Flavour of Seesaw.
Minimal Flavour Violation in the lepton sector is presented. It is
explored whether it is compatible with a) neutrino mass generation at
tree level (Seesaw models) and b) a separation of the scales at which
lepton number and flavour violation occur. We present an extremely
simple model of neutrino masses, compatible with MFV, in which the
full high-energy couplings can be reconstructed from the low energy
observables, including CP-violating phases.
|
| 18:15-18:30 |
Jackson Wu (Bern U.): Dirac Neutrino in Warped Extra Dimensions
We implement Dirac neutrinos in the minimal custodial Randall-Sundrum
setting via the Krauss-Wilczek mechanism. We demonstrate by giving
explicit lepton mass matrices that with neutrinos in the normal
hierarchy, lepton mass and mixing patterns can be naturally reproduced
at the scale set by the constraints from electroweak precision
measurements, and at the same time without violating bounds set by
lepton flavour violations. Our scenario generically predicts a nonzero
neutrino mixing angle $\theta_{13}$, as well as the existence of
sub-TeV right-handed Kaluza-Klein neutrinos, which partner the
right-handed Standard Model charged leptons. These relatively light KK
neutrinos may be searched for at the LHC.
|
| 18:30-18:45 |
Chee Sheng Fong (YITP, Stony Brook): Flavour in Soft Leptogenesis
Leptogenesis is an attractive mechanism to explain the baryon
asymmetry of the universe and the tiny masses of the light neutrinos.
The simplest scenario is to introduce singlet fermion(s) in the
Standard Model (Type-I seesaw). If supersymmetry (SUSY) is also
realized in nature, it has to be broken for the fact that we haven't
seen any of the superpartners. Without knowing the exact mechanism of
SUSY breaking, the best we can do is to introduce all possible soft
SUSY breaking terms in the Lagrangian that doesn't reintroduce
quadratic divergences. With these, we obtain a possible leptogenesis
scenario at the scale $M=10^5-10^8$ GeV termed soft leptogenesis. In
this regime, we will see that thermal and lepton flavour effects play
a crucial role. In particular, we will investigate thoroughly how
large flavour enhancement is possible taken into account the flavour
equilibration interactions induced by off-diagonal slepton masses.
|
| 18:45-19:00 |
Pablo Villanueva Perez (Valencia U.): Model independent observation of T-Violation.
This talk describes an analysis to perform for the first time a
SEPARATE and INDEPENDENT evidence for T violation (and CP violation)
in B-factories. Although all present test of CPT invariance confirm
this symmetry, imposed by any local quantum field theory with Lorentz
invariance.
|
| 19:00-19:15 |
Marc Ramon (UAB - Barcelona): Measuring $\sin\phi_s$ from NP-polluted decays
We discuss a new approach to measure the weak mixing angle $\phi_s$ of
the $B_s$ system in presence of New Physics (NP) in the mixing and in
the amplitude. We present a new expression that allow to obtain
directly $\sin\phi_s^{NP}$ if there is only a significant contribution
of NP in the mixing and also a corresponding one if NP is present in
both mixing and amplitude.
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