Calculation of associated production of a top quark and aW′at the LHC

Abstract

We investigate collider signatures of a top-philic W ′ model, in which the W ′ boson couples only to the third-generation quarks of the standard model. The main discovery channel for this W ′ is through associated production of the W ′ and top quark, yielding a top-quark pair plus an extra bottom quark jet as a signal. We do a full simulation of the signal and relevant backgrounds. We develop a method of analysis that allows us to conclude that discovery of the W ′ is promising at the LHC despite large standard model backgrounds. Bottom quark tagging of the extra jet is key to suppressing the backgrounds.

Cosmic opacity: Cosmological-model-independent tests from gravitational waves and Type Ia Supernova

“…One of the most important issues of the modern cosmology lies in the discovery that our universe is undergoing an accelerated expansion at the present stage, through the observations of unexpected dimming of type Ia supernovae (SNe Ia) [1]. In the framework of general relativity (GR), a mysterious substance with negative pressure, dubbed as dark energy, was proposed to explain this acceleration [2][3][4][5][6][7]. However, another mechanism attempts to explain this observed SNe Ia dimming, i.e., whether the light intensity of a supernova is diminished because of the photon absorption or scattering of dust in Milky Way, intervening galaxies or the host galaxy [8].…”

Top-philic scalar Dark Matter with a vector-like fermionic top partner

“…Consequently, it is well motivated to connect the DM sector to top quark and a specially interesting scenario is the DM which couples only to the top quark sector. Some top-philic new particle sectors and/or DM models can be found in [8][9][10][11][12][13][14][15][16][17] and the references therein. Different from previous studies, in this work we consider a top-philic scalar DM model by extending the above Higgs portal model with a vector-like fermionic particle T (topVL) which is also odd under the unbroken discrete Z 2 symmetry.…”

LHC phenomenology of generalSU(2)×SU(2)×U(1)Ježo1, Klasen2, Schienbein3 2012Phys. Rev. D260320View full textAdd to dashboardCite

“…of pairs of leptons [6], top quarks [7], their associated production with W 0 bosons [8], or measurements of the top quark polarization [7,9,10]. In this Letter, we demonstrate that total cross sections for lepton and third-generation quark production, while easily accessible at the LHC, allow for a unique identification of the correct G(221) model only when correlated among each other in the neutral current (NC) and charged current (CC) channels.…”