Erdei fás növények válaszreakciója környezeti tényezők változásának hatására = Response for forest trees to changing environmental conditions

A klímaváltozás előrejelzése indokolja a fás növények válaszreakciójának tanulmányozását. A Leltározó Lucfenyő Származási Kísérletsorozat (IUFRO 1964/68) magyarországi és svédországi kísérleteinek 16 éves kori növekedési adatait elemeztük. Megállapítottuk, hogy a magassági növekedés változatosságának 78 %-át a klímaparaméterek határozzák meg. A fiatalkori változatosságot elsősorban a hőösszeg-változás determinálja. Az elemzések megkönnyítésére a lucfenyő elterjedési területén 10 zónacsoportot alakítottunk ki. A kísérleti hely, valamint a származási hely közötti hőösszeg-változás növekedésre gyakorolt hatása zónacsoportonként matematikai függvények segítségével kifejezhető. Mindezek ismeretében klímaváltozás esetén a lucfenyő válaszreakciója modellezhető. | Inventory Provenance Test with Norway Spruce (IUFRO 1964/68) in Hungary and Sweden were used for assessing the effects of the projected climatic change on forest trees. To get a clear picture of the large scale geographic variation 10 zone groups have been constructed. The temperature sum in growing season and the precipitation sum before vegetation period have been used to characterize the climate at the individual locations. A model can be constructed with the estimated changes in height growth as a function of the temperature sum at the original location and the change in the temperature sum caused by the geographical transfer

Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at root s=13 TeV

A search for physics beyond the standard model is performed using a sample of high-mass diphoton events produced in proton-proton collisions at $\sqrt{s} =$ 13 TeV. The data sample was collected in 2016 with the CMS detector at the LHC and corresponds to an integrated luminosity of 35.9 fb$^{-1}$. The search is performed for both resonant and nonresonant new physics signatures. At 95% confidence level, lower limits on the mass of the first Kaluza-Klein excitation of the graviton in the Randall-Sundrum warped extra-dimensional model are determined to be in the range of 2.3 to 4.6 TeV, for values of the associated coupling parameter between 0.01 and 0.2. Lower limits on the production of scalar resonances and model-independent cross section upper limits are also provided. For the large extra-dimensional model of Arkani-Hamed, Dimopoulos, and Dvali, lower limits are set on the string mass scale $M_S$ ranging from 5.6 to 9.7 TeV, depending on the model parameters. The first exclusion limits are set in the two-dimensional parameter space of a continuum clockwork model

Simulation of the dynamic inefficiency of the CMS pixel detector

The Pixel Detector is the innermost part of the CMS Tracker. It therefore has to prevail in the harshest environment in terms of particle fluence and radiation. There are several mechanisms that may decrease the efficiency of the detector. These are mainly caused by data acquisition (DAQ) problems and/or Single Event Upsets (SEU). Any remaining efficiency loss is referred to as the dynamic inefficiency. It is caused by various mechanisms inside the Readout Chip (ROC) and depends strongly on the data occupancy. In the 2012 data, at high values of instantaneous luminosity the inefficiency reached 2% (in the region closest to the interaction point) which is not negligible. In the 2015 run higher instantaneous luminosity is expected, which will result in lower efficiencies; therefore this effect needs to be understood and simulated. A data- driven method has been developed to simulate dynamic inefficiency, which has been shown to successfully simulate the effects

Search for supersymmetry in events with a τ lepton pair and missing transverse momentum in proton-proton collisions at √s=13 TeV

A search for the electroweak production of supersymmetric particles in proton-proton collisions at a center-of-mass energy of 13 TeV is presented in final states with a $\tau$ lepton pair. Both hadronic and leptonic decay modes are considered for the $\tau$ leptons. Scenarios involving the direct pair production of $\tau$ sleptons, or their indirect production via the decays of charginos and neutralinos, are investigated. The data correspond to an integrated luminosity of 35.9 fb$^{-1}$ collected with the CMS detector in 2016. The observed number of events is consistent with the standard model background expectation. The results are interpreted as upper limits on the cross section for $\tau$ slepton pair production in different scenarios. The strongest limits are observed in the scenario of a purely left-handed $\tau$ slepton with a mass of 90 GeV decaying to a nearly massless neutralino, and correspond to 1.26 times the expected production cross section in the simplified model considered. Exclusion limits are also set in the context of simplified models of chargino-neutralino and chargino pair production with decays to $\tau$ leptons, and range up to 710 and 630 GeV, respectively

Studies of dijet pseudorapidity distributions and transverse momentum balance in pPb collisions at √sNN=5.02 TeV

Dijet production has been measured in pPb collisions at a nucleon-nucleon centre-of- mass energy of 5.02 TeV. A data sample corresponding to an integrated luminosity of 35 nb−1 was collected using the Compact Muon Solenoid detector at the Large Hadron Collider. The dijet transverse momentum balance, azimuthal angle corre- lations, and pseudorapidity distributions are studied as a function of the transverse energy in the forward calorimeters (E4<|η|<5.2 T ). For pPb collisions, the dijet transverse momentum ratio and the width of the distribution of dijet azimuthal angle differ- ence are comparable to the same quantities obtained from a simulated pp reference and insensitive to E4<|η|<5.2 T . In contrast, the mean value of the dijet pseudorapidity is found to change monotonically with increasing E4<|η|<5.2 T , indicating a correlation between the energy emitted at large pseudorapidity and the longitudinal motion of the dijet frame. The pseudorapidity distribution of the dijet system in minimum bias pPb collisions is compared with next-to-leading-order perturbative QCD predictions obtained from both nucleon and nuclear parton distribution functions, and the data more closely match the latter

Search for new phenomena in events with high jet multiplicity and low missing transverse momentum in proton–proton collisions at

A dedicated search is presented for new phenomena in inclusive 8- and 10-jet final states with low missing transverse momentum, with and without identification of jets originating from b quarks. The analysis is based on data from proton–proton collisions corresponding to an integrated luminosity of 19.7 fb−1 collected with the CMS detector at the LHC at √s = 8 TeV. The dominant multijet background expectations are obtained from low jet multiplicity control samples. Data agree well with the standard model background predictions, and limits are set in several benchmark models. Colorons (axigluons) with masses between 0.6 and 0.75 (up to 1.15) TeV are excluded at 95% confidence level. Similar exclusion limits for gluinos in R-parity violating supersymmetric scenarios are from 0.6 up to 1.1 TeV. These results comprise the first experimental probe of the coloron and axigluon models in multijet final states. © 2017 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY licenseL