Jyothsna Rani Komaragiri

The measurement of t-channel single top cross-section in proton–proton collisions at the Large Hadron Collider (LHC) at a centre-of-mass energy of 7 TeV, using data collected with the Compact Muon Solenoid (CMS) experiment during the year 2010 is presented. Both the electron-neutrino and muon-neutrino decay channels of W boson from top decay are considered. Two complementary multivariate analysis methods to separate signal and background and to extract the cross-section for the single top produced in t-channel are explored. The result is compared with the most precise Standard Model theory predictions.

Dark Matter is a hypothetical particle proposed to explain the missing matter expected from the cosmological observation. The motivation of Dark Matter is overwhelming however as it is mainly deduced from its gravitational interaction, for it does little to pinpoint what Dark Matter really is. In WIMPs Miracle, weakly interactive massive particle being the Dark Matter candidate is correctly producing the current thermal relic density at weak scale, implying the possibility of producing and detecting it in Large Hadron Collider. Assuming WIMPs being the maverick particle within collider, it is expected to be pair produced in association with a Standard Model particle. The presence of the WIMPs pair is inferred from the Missing Transverse Energy (MET) which is the vector sum of the imbalance in the transverse momentum plane recoils a Standard Model Particle. The collider is able to produce light mass Dark Matter which the traditional detection fail to detect due to the small momentum transfer involved in the interaction; on the other hand, the traditional detection is robust in detecting a higher Dark matter masses but the collider is suffered from the parton distribution function suppression. Topologically the processes are similar to the scattering processes in the direct detection thus complementary to the traditional Dark Matter detection. The collider searches are strongly motivated as the results are usually translated to the annihilation and scattering rates at more traditional Dark Matter-oriented experiments, thus a concordance approach is adapted. An overview of Dark Matter searches at the Large Hadron Collider will be covered in this paper.

Understanding the physical world is a continuous process of trial and error. It requires theoretical background and tools to find out the theory's accuracy. Particles motion through matter, and their energy loss is one such process. Testing the energy loss requires the development of a tool capable of simulating and testing theoretical predictions using data. For this very reason, researchers developed a Monte-Carlo based simulation toolkit, the Geant4 project. A multi-purpose toolkit to explore the nature of collisions and energy loss of particles. Uses of Geant4 are in fields where particle interaction is required, ranging from high energy physics to medical physics and space physics research. Its physics component offers various simulations packages and tools to study the processes involved. The study uses the electromagnetic package to verify the Bethe-Bloch energy loss formula for charged particles developed mainly by Hans Bethe and analyse the extent of its validity.

We present the status and performance of the physics objects with data corresponding to an integrated luminosity of 12.9 inverse fb collected at 13 TeV by the CMS experiment. We cover the performance of the physics objects extensively used in physics analyses involving top quarks.

Charge-dependent anisotropy Fourier coefficients ($v_n$) of particle azimuthal distributions are measured in pPb and PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 5.02 TeV with the CMS detector at the LHC. The normalized difference in the second-order anisotropy coefficients ($v_2$) between positively and negatively charged particles is found to depend linearly on the observed event charge asymmetry with comparable slopes for both pPb and PbPb collisions over a wide range of charged particle multiplicity. In PbPb, the third-order anisotropy coefficient, $v_3$, shows a similar linear dependence with the same slope as seen for $v_2$. The observed similarities between the $v_2$ slopes for pPb and PbPb, as well as the similar slopes for $v_2$ and $v_3$ in PbPb, are compatible with expectations based on local charge conservation in the decay of clusters or resonances, and constitute a challenge to the hypothesis that the observed charge asymmetry dependence of $v_2$ in heavy ion collisions arises from a chiral magnetic wave.

We summarize direct measurements of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element, V tb , using single top quark events at the ATLAS and CMS experiments and an indirect measurement of V tb using top quark pair events at CMS experiment of CERN LHC based on the data collected at different center-of-mass energies of 7, 8 and 13 TeV.

The search for aCarvalho, Alexandra massive resonance produced by vector boson fusion and decaying into a pair of Higgs bosons,Komaragiri, Jyothsna Rani each decaying to a b quark-antiquark pair, at the High Luminosity Large Hadron Collider in proton-proton collisions at a centre-of-mass energy of 14 TeV is explored.Majumder, Devdatta The Higgs bosons are required to be sufficiently Lorentz-boosted for each to be reconstructed using a single large-area jet.Panwar, Lata We study the signal sensitivity for a narrow bulk graviton in extradimensional scenarios using a simulation of the upgraded CMS detector, assuming multiple proton-proton collisions in the same bunch crossing (up to 200), for data corresponding to an integrated luminosity of 3 ab $$^{-1}$$ . The expected significance for different assumed masses of the bulk graviton is presented.