arXiv subjects

Didar Dobur

Publications and source records attributed to Didar Dobur.

6 recordsLinked to original sources

arXiv2026

A Pythia8 Tune for Open Charm and Beauty Production in Fixed-Target Collisions

We present FTFT (Fixed-Target Fragmentation Tune), a set of Pythia8 parameters optimised for the production of charm and beauty hadrons in fixed-target collisions at centre-of-mass energies $\sqrt{s} \simeq 20-42$ GeV. Accurate heavy-flavour production in this regime is needed to predict neutrino fluxes and hidden-particle yields at beam-dump experiments such as SHiP. The tune is derived in two stages. First, differential distributions in Feynman-$x$ ($x_F$), transverse momentum squared ($p_T^2$), and charge or leading-particle production asymmetry of $D$ mesons are fitted to data from pion- and proton-beam fixed-target experiments. Second, $K$-factors for each beam are extracted from inclusive charm cross-section measurements to scale the simulated cross section to the measured data. The fitted charm-fragmentation and multiparton-interaction parameters depart from standard LHC-tuned defaults, in line with earlier fixed-target studies.

hep-ex↗

arXiv2021

Photon radiation effects in kinematic reconstruction of top quarks

Kinematic reconstruction of top quarks allows to define a set of kinematic observables relevant to various physics processes that involve top quarks and provides an additional handle for the suppression of background events. Radiation of photons in association with the top quarks alters the kinematics and the topology of the event, leading to visible systematic effects in measurable observables. The present study introduces an improved reconstruction of the top quark kinematics in the presence of photon radiation. The results are presented for processes with top quark pair production, as well as for singly-produced top quarks.

hep-ex↗

arXiv2015

Probing top-philic sgluons with LHC Run I data

Many theories beyond the Standard Model predict the existence of colored scalar states, known as sgluons, lying in the adjoint representation of the QCD gauge group. In scenarios where they are top-philic, sgluons are expected to be copiously pair-produced at the LHC via strong interactions with decays into pairs of top quarks or gluons. Consequently, sgluons can be sought in multijet and multitop events at the LHC. We revisit two LHC Run I analyses in which events featuring either the same-sign dileptonic decay of a four-top-quark system or its single leptonic decay are probed. Adopting a simplified model approach, we show how this reinterpretation allows us to extract simultaneous bounds on the sgluon mass and couplings.

hep-ph↗

arXiv2009

W and Z boson Productions in CMS at LHC startup

We report on potential for measurement of W and Z boson production, as well as the production in association with jets. Of particular interest are jet multiplicity and $P_{\rm T}$ distributions. The 10 to $100 {\rm pb}^{-1}$ datasets expected in the startup year of operation of LHC are likely to already provide information beyond the reach of the Tevatron collider both in jet multiplicity and $P_{\rm T}$ range. We are especially interested in understanding the ratios of W+jets to Z+jets distributions by comparing them to next-to-leading order Monte Carlo generators, as these processes present a formidable background for searches of new physics phenomena.

hep-ex↗

arXiv2009

Jets and Missing Transverse Energy Reconstruction with CMS

We report on the current simulation studies regarding the reconstruction of Jets and Missing Transverse Energy (MET) with the CMS detector at the CERN proton-proton LHC accelerator. The performance of various jet algorithms is compared, when using calorimeter energy deposits as inputs to the algorithm. The plan for obtaining jet energy corrections is outlined and data-driven correction methods are described. Finally, the performance of MET reconstruction is summarized.

hep-ex↗

arXiv2009

Production of jets accompanied by W and Z bosons at LHC startup

We report on potential for measurement of W and Z boson production accompanied by jets. Of particular interest are jet multiplicity and $P_{\rm T}$ distributions. The 10 to 100 $pb^{-1}$ datasets expected in the startup year of operation of LHC are likely to already provide information beyond the reach of the Tevatron collider both in jet multiplicity and $P_{\rm T}$ range. We are especially interested in understanding the ratios of W+jets to Z+jets distributions by comparing them to next-to-leading order Monte Carlo generators, as these processes present a formidable background for searches of new physics phenomena.

hep-ex↗