Conveners
Parallel II: SUSY/Higgs
- Andreas Jung (Purdue University (US))
Parallel II: SUSY/EW extensions
- Farid Ould-Saada (University of Oslo (NO))
Parallel II: QCD/strong interactions
- Bjoern Penning (Imperial College Sci., Tech. & Med. (GB))
Parallel II: 750 GeV Resonance
- Anna Goussiou (University of Washington (US))
Searches for additional scalars and pseudoscalar with masses below the newly discovered higgs boson h(125) are performed at CMS experiment . These searches are motivated within several BSM theories, most significantly extensions of the mininal extensions of the MSSM like the NMSSM, where additional scalar and pseudoscalar states are expected. The mass range from 250 MeV to 110 GeV is explored...
Higgs-boson pair production is well known being capable to probe the trilinear self-coupling of the Higgs boson, which is one of the important ingredients of the Higgs sector itself. Pair production then depends on the top-quark Yukawa coupling gS,Pt, Higgs trilinear coupling λ3H, and a possible dim-5 contact-type ttHH coupling gS,Ptt, which may appear in some higher representations of the...
We consider the tentative hint of Higgs boson decay h→μτ recently seen in LHC data in a grand unified theory framework which is based on the SU(5) gauge group and implements the principle of minimal flavor violation. This allows us to explore the possibility that this decay has some link to potential new physics in the quark sector. We look at different simple scenarios in this context and...
We perform the one-loop induced charged lepton flavor violating decays of the neutral Higgses in an extended mirror fermion model with non-sterile electroweak-scale right- handed neutrinos and a horizontal A4 symmetry in the lepton sector. We demonstrate that for the 125 GeV scalar h there is tension between the recent LHC result B(h → τμ) ∼ 1% and the stringent limits on the rare processes μ...
We consider two-Higgs doublet models (THDMs) with a supersymmetric UV completion. Contrary to the Standard Model, THDMs can be embedded in high-scale supersymmetry with a SUSY breaking scale as high as the scale of grand unification. The stability of the electroweak vacuum and experimental constraints point towards low values of tan(beta) < 2 and a pseudoscalar mass of at least about a TeV. If...
LHC Run I discovered the Higgs boson and revealed that it has properties almost
predicted by the SM, like spin, parity and couplings to the other SM particles.
If there exists additional light bosons having the same quantum numbers with the Higgs boson, they will mix with it through the off-diagonal mass terms.
This mixings modify the couplings of the Higgs boson and also generate...
We consider a class of minimal abelian extensions of the Standard Model (SM) with an extra neutral gauge boson Z’ at the TeV scale. In these scenarios an extended scalar sector and heavy right-handed neutrinos are naturally envisaged. We present some of their striking signatures at the Large Hadron Collider, the most interesting
arising from a Z’ decaying to heavy neutrino pairs as well as...
We study the sensitivity of top pair production and six-fermion decay at the LHC to the presence and nature of an underlying Z' boson, accounting for full tree-level Standard Model interference, with all intermediate particles allowed off-shell. We concentrate on the lepton-plus-jets final state and simulate experimental considerations, including kinematic requirements and top quark pair...
Observation of non-zero neutrino masses at a scale $\sim 10^{-1} - 10^{-2}$ eV is a major problem in otherwise highly successful Standard Model. The most elegant mechanism to explain such tiny neutrino masses is seesaw mechanism with right handed neutrinos. However, the required seesaw scale is so high ($\sim 10^{14}$ GeV), it will not have any direct collider implications. Recently, in our...
In our work, we investigate exclusion limits on the parameter space of the Non-Universal Gaugino Mass (NUGM) scenario
where a natural SUSY spectrum is achieved due to a relatively heavy wino mass parameter. We calculated the bound on the mass of top squark, which is almost right-handed and then it can decay into both $t \tilde{\chi}_{1,2}^0$ and $b \tilde{\chi}_1^{\pm}$. The top squark...
I discuss the Yukawa unification, in particular, the unification
of the Yukawa coupling constants of bottom and tau, in the
framework of supersymmetric (SUSY) model. I concentrate on the
model in which the SUSY breaking scalar masses are of the order
of the gravitino mass while the gaugino masses originate from the
effect of anomaly mediation and hence are one-loop suppressed
relative...
The Pierre Auger Observatory is the largest detector ever built. With an area covering over 3000 km2, it was designed for the detection of ultra high energy cosmic rays. Using an original hybrid technique the Observatory can measure both the longitudinal profile in the atmosphere and the lateral distribution of particles at the ground, which allows the study of the extensive air showers in two...
A photon is a fundamental particle, instead of a nonperturbative composite like hadrons. However, an energetic photon can fluctuate into vector mesons in the kinematic region with a small Bjorken variable x < 0.1. Particularly at x < 0.01, the hadronic contribution to cross sections of the electron–photon deep inelastic scattering dominates, and a photon can be regarded as a hadron rather than...
I discuss a new axionic solution to the strong CP problem which involves a hypothetical vector-like quark(s) in a high-colour representation of the conventional QCD. There are two distinct scenarios. If the current mass of the exotic quark is zero, the strong CP phase can be trivially rotated away. The high-colour quark is `hidden' in various bounds states, the lightest being the composite...
As Rubakov suggested in 1997, an QCD axion can be heavy if there is a copy of
the Standard Model and a Peccei-Quinn symmetry is realized between it and the
Standard Model.
Following that idea, we construct a concrete model which satisfies the cosmological
consistency.
Then, some of the resultant particles can be around the region which is accessible by
the LHC. We point out that the...
A search for resonances decaying to two photons was conducted with the ATLAS Experiment at the LHC. The analysis used proton-proton collision data with a center-of-mass energy of sqrt(s)=13 TeV and an integrated luminosity of 3.2/fb. Searches were performed for spin-0 particles at masses greater than 200 GeV and spin-2 particles at masses greater than 500 GeV. Limits on the production...
We investigate the possibility that the widely discussed $\sim 750$ GeV $\gamma\gamma$ excesses at the 2015 $13 TeV$ collisions at the LHC can be explained by the vector boson fusion production rather than the gluon-gluon fusion production which was assumed by most of the phenomenological models, by considering the available kinematics distributions from ATALS and CMS results. We propose a...
The diphoton excess at 750 GeV would make a definite signal of new physics beyond the Standard Model, if it is confirmed. We consider a possibility that the excess is due to a composite (pseudo)scalar boson, whose constituents are either new vector-like quarks ($Q\overline{Q}$) or scalar quarks
($\widetilde{Q} \widetilde{Q}^\dagger$) which feel new QCD-like vectorlike confining force
with...
Motivated by the di-photon resonance recently reported by the ATLAS and CMS collaborations at 13 TeV, we interpret the resonance as a scalar boson X(750) in hidden-valley-like models. The scalar boson X can mix with the standard model Higgs boson and thus can be produced via gluon fusion. It then decays into a pair of very light hidden particles Y of sub-GeV, each of which in turn decays to a...
In this talk I will first show how the relatively large effective couplings, required by the 750 GeV diphoton signal, can be the result of a threshold enhancement in the loop coupling between a heavy pseudoscalar particle and new leptons and quarks with masses of about 375 and 700 GeV, respectively. I will then present a model in which the new charged leptons avoid detection by decaying to a...
