P. Cirkovic

Recent LHC results on the appearance of sub-leading flow modes in PbPb collisions at 2.76~TeV, related to initial-state fluctuations, are analyzed and interpreted within the HYDJET++ model. Using the newly introduced Principal Component Analysis (PCA) method applied to two-particle azimuthal correlations extracted from the model calculations, the leading and the sub-leading flow modes are studied as a function of the transverse momentum ($p_{T}$) over a wide centrality range. The leading modes of the elliptic ($v^{(1)}_{2}$) and triangular ($v^{(1)}_{3}$) flow calculated within the HYDJET++ model reproduce rather well the $v_{2}\{2\}$ and $v_{3}\{2\}$ coefficients experimentally measured using the two-particle correlations. Within the $p_{T} \le $~3~GeV/c range where hydrodynamics dominates, the sub-leading flow effects are greatest at the highest $p_{T}$ of around 3~GeV/c. The sub-leading elliptic flow mode ($v^{(2)}_{2}$), which corresponds to $n = 2$ harmonic, has a small non-zero value and slowly increases from central to peripheral collisions, while the sub-leading triangular flow mode ($v^{(2)}_{3}$), which corresponds to $n = 3$ harmonic, is even smaller and does not depend on centrality. For $n = $~2, the relative magnitude of the effect measured with respect to the leading flow mode shows a shallow minimum for semi-central collisions and increases for very central and for peripheral collisions. For $n = $~3 case, there is no centrality dependence. The sub-leading flow mode results obtained from the HYDJET++ model are in a rather good agreement with the experimental measurements of the CMS Collaboration.

The Detector Control System of the CMS Electromagnetic Calorimeter has undergone significant improvements during the first LHC Long Shutdown. Based on the experience acquired during the first period of physics data taking of the LHC, several hardware projects were carried out to improve data accuracy, to minimise the impact of failures and to extend remote control possibilities in order to accelerate recovery from problematic situations. This paper outlines the hardware of the detector control and safety systems and explains in detail the requirements, design and commissioning of the new hardware projects.

Characterization of a graph by its spectrum is a very attractive research problem that has numerous applications. It is shown that the graph is not necessarily uniquely determined by its spectrum in the most general case, i.e., there could be several non-isomorphic graphs corresponding to the same spectrum. All such graphs are called cospectral. However, in most of the cases, it is important to find at least one graph whose spectrum is equal to a given constant vector. This process is called Spectral Reconstruction of Graph (SRG) and it is known as one of the most difficult optimization problems. We address the SRG problem by the metaheuristic methods, more precisely, by Basic Variable Neighborhood Search (BVNS) and improvement-based Bee Colony Optimization (BCOi) methods. The resulting heuristics are called SRG-BVNS and SRG-BCOi, respectively. Both methods are implemented in such a way to take into account the graph properties defined by its spectrum. We compare the performance of the proposed methods with each other and with the results obtained by other approaches from the relevant literature on the reconstruction of some well-known graphs.

The first long shutdown of the Large Hadron Collider (LS1, 2013-2015) provided an opportunity for significant upgrades of the detector control and safety systems of the CMS Electromagnetic Calorimeter. A thorough evaluation was undertaken, building upon experience acquired during several years of detector operations. Substantial improvements were made to the monitoring systems in order to extend readout ranges and provide improved monitoring precision and data reliability. Additional remotely controlled hardware devices and automatic software routines were implemented to optimize the detector recovery time in the case of failures. The safety system was prepared in order to guarantee full support for both commercial off-the-shelf and custom hardware components throughout the next accelerator running period. The software applications were modified to operate on redundant host servers, to fulfil new requirements of the experiment. User interface extensions were also added to provide a more complete overview of the control system. This paper summarises the motivation, design, implementation and validation of the major improvements made to the hardware and software components during LS1. Presented at ICALEPCS 2015 15th International Conference on Accelerator and Large Experimental Physics

Bone and soft tissue tumors are rare. There is a variety of types and each one has its own particular behavior, treatment and patient outcome. The assessment of treatment response following the 3rd cycle of chemotherapy is one of the most important aspects of patient care, as therapeutic options and the timing of surgery may vary depending on the achievement of response. Hence, we focused on the advanced imaging technique, proton magnetic resonance spectroscopy (1H MRS), aiming at improving the diagnostic accuracy and the tumor response to therapy, based on the absolute concentration of choline (Cho) as biomarker of malignancy.Twenty patients were studied. All of them had a pathological diagnosis after biopsy. MRI examinations were performed using a 1.5 T MR scanner (Avanto; Siemens, Erlangen, Germany). Single-voxel 1H MR spectroscopy was performed by using a PRESS with TR/TE 1530/100 ms, before chemotherapy and after the 3rd cycle. 1H MRS was processed in LCmodel.Of 20 patients, 7 responded to neoadjuvant chemotherapy and 13 did not. In responders, the mean concentration of tCho before therapy was 4.7±2.5 mmol/kg, which showed statistically significant reduction after therapy. In non-responders, the mean tCho concentration before therapy was 2.9±0.9 mmol/kg which remained the same or increased after the 3rd cycle of neoadjuvant chemotherapy (2.7±2.5 mmol/kg; range from 2.05 to 5.79 with no statistical significance). Compared to reference healthy group, tCho concentrations were increased in all cases.1H MRS appears to be valuable technique for evaluation of response to neoadjuvant chemotherapy of patients with musculoskeletal tumors (MSK).

In this paper, the latest results of searches for the standard model Higgs boson produced in association with a top quark-antiquark pair ($\mathrm{t\bar{t}H}$), where Higgs decays into photons, bottom quark-antiquark pair or leptons via $\mathrm{WW^*}$, $\mathrm{ZZ^*}$ and $\mathrm{ττ}$ will be presented. The analyses have been performed using the $\mathrm{13\,TeV}$ pp collisions data recorded by the CMS experiment in 2015 and part of 2016. The results are presented in the form of the best fit to the signal strength ($\mathrm{μ=σ/σ_{SM}}$) measured with respect to the Standard Model prediction and its expected and observed $\mathrm{95\%}$ C.L. upper limits.

The latest results of searches for the standard model Higgs boson produced in association with a top quark-antiquark pair (tt̄H), where Higgs decays into photons, bottom quark-antiquark pair or leptons via WW, ZZ and ττ are presented. The analyses have been performed using the 13 TeV pp collisions data recorded by the CMS experiment in 2015 and part of 2016. The results are presented in the form of the best fit to the signal strength (μ = σ/σSM) measured with respect to the Standard Model prediction and its expected and observed 95% CL upper limits.

Mössbauer spectra of human liver ferritin and its pharmaceutical analogues Ferrum Lek and Maltofer® measured at various temperatures within the range of 295–83 K were fitted using five quadrupole doublets related to different 57Fe microenvironments in various layers/regions of the ferrihydrite and akaganéite iron cores. The observed anomalous temperature dependences of some Mössbauer parameters were considered as a result of low temperature structural rearrangements in different layers/regions in the iron core.

An overview of the standard model Higgs boson analyses and beyond standard model Higgs boson searches will be given. A data sample of proton-proton collisions at collected with the CMS detector at the LHC is used. The measurements of properties of the Higgs boson in the 4ℓ and γγ decay channels will be presented. The future prospects will be covered.

A search for flavor-changing neutral current (FCNC) processes in associated production of a top quark and Higgs boson, with the Higgs boson decaying to a pair of b quarks, is presented. To experimentally probe the top-Higgs FCNC couplings, for the first time the single-top production is considered as a signal process. One isolated lepton and at least three reconstructed jets, among which at least two are identified as b quark jets, are found in the final state. The data sample corresponds to an integrated luminosity of $35.9\,\mathrm{fb^{-1}}$ recorded by the CMS experiment at the LHC in proton-proton collisions at $\sqrt{s}\,=\,13\,\mathrm{TeV}$ in 2016, and the final results are presented in the form of the observed and expected 95\% CL upper limits on the branching ratio of top quark decays.

The elliptic flow (${v}_{2}$) event-by-event fluctuations in PbPb collisions at 5.02 TeV are analyzed within the $\mathrm{HYDJET}++$ model. Using the multiparticle, so-called $Q$-cumulant method, ${v}_{2}{2}$, ${v}_{2}{4}$, ${v}_{2}{6}$, and ${v}_{2}{8}$ are calculated and used to study their ratios and to construct skewness (${\ensuremath{\gamma}}_{1}^{\mathrm{exp}}$) as a measure of the asymmetry of the elliptic flow distribution. Additionally, in order to check if there is a hydrodynamics nature in the elliptic collectivity generated by the $\mathrm{HYDJET}++$ model, the ratio of ${v}_{2}{6}\ensuremath{-}{v}_{2}{8}$ and ${v}_{2}{4}\ensuremath{-}{v}_{2}{6}$ distributions is calculated. The analysis is performed as a function of the collision centrality. In order to check the $\mathrm{HYDJET}++$ model responses, the results of this analysis are compared to the corresponding experimental measurements from the ALICE, ATLAS, and CMS experiments. A rather good qualitative agreement is found.

The LHC results on the sub-leading flow modes in PbPb collisions at 2.76 TeV, related to initial-state fluctuations, are analyzed and interpreted within the HYDJET++ model. Using the newly introduced Principal Component Analysis (PCA) method applied to two-particle azimuthal correlations extracted from the model calculations, the leading and the sub-leading flow modes are studied as a function of the transverse momentum (pT ) over a wide centrality range. The leading modes of the elliptic (v (1) 2 ) and triangular (v 3 (1) 3) flow calculated within the HYDJET++ model reproduce rather well the v 2 {2} and v 3 {2} coeffcients experimentally measured using the two-particle correlations. Within the pT ≤3 GeV/c range where hydrodynamics dominates, the sub-leading flow effects are greatest at the highest pT of around 3 GeV/c. The sub-leading elliptic flow mode (v 2 (2) ), which corresponds to n=2 harmonic, has a small non-zero value and slowly increases from central to peripheral collisions, while the sub-leading triangular flow mode (v 3 (2) ), which corresponds to n =3 harmonic, is even smaller and does not depend on centrality. For n =2, the relative magnitude of the effect measured with respect to the leading flow mode shows a shallow minimum for semi-central collisions and increases for very central and for peripheral collisions. For n =3 case, there is no centrality dependence. The subleading flow mode results obtained from the HYDJET++ model are in a rather good agreement with the experimental measurements of the CMS Collaboration.