Three-photon productions within the $$k_t$$-factorization at the LHC

Recently, the ATLAS data of isolated three-photon production showed that the next-to-leading order (NLO) collinear factorization is not enough to describe experimental data. Therefore, one needs to calculate the cross section beyond the NLO, and as showed later, these data can be well described by the NNLO calculation within the collinear factorization framework. However, it is shown that the $$k_t$$ k t -factorization can be quite successful in describing exclusive and high energy collision processes, henceforth we decided to calculate isolated three-photon production within this framework. In this work we use the Martin, Ryskin, and Watt unintegrated parton distribution functions (MRW UPDFs) at LO and NLO levels, in addition to parton branching (PB) UPDFs in order to calculate cross section which we utilize the KATIE parton level event generator. It will be shown that in contrast to collinear factorization, the $$k_t$$ k t -factorization can describe quiet well the three-photon production ATLAS data. Interestingly our results using the NLO-MRW and PB UPDFs can cover the data within their uncertainty bands, similar to the NNLO collinear results.

Theoretical and Experimental Study of the Pounding Response for Adjacent Inelastic MDOF Structures Based on Dimensional Analysis

Dimensional analysis is applied to study the pounding response of two inelastic multidegree of freedom (MDOF) structures under simplified earthquake excitation. The forces and deformations of the collision processes are simulated by adopting the improved Kelvin pounding model. The inelastic characteristics of MDOF structures are described by the bilinear interstory resistance model, and the representations of dimensionless impact force and the dimensionless motion equation in the pounding process are derived. On the basis of the above-mentioned theoretical deduction, the superiority of the improved Kelvin model is verified by comparing the impact response of the improved Kelvin model and the Kelvin model. Finally, the validity of the proposed theoretical method is further proved by the comparison between results from the shaking table tests of adjacent four-story and three-story steel frame structures and the corresponding numerical results obtained by the MATLAB program.

On the Quantum Mechanics of Collision Processes [English Translation]

An examination of collision processes indicates that Schrödinger’s quantum mechanics describes not only stationary states, but also quantum jumps.

Simulating the FIP effect in coronal loops using a multi-species kinetic-fluid model

<p>We investigate abundance variations of heavy ions in coronal loops. We develop and exploit a multi-species model of the solar atmosphere (called <em>IRAP’s Solar Atmospheric Model</em>: <em>ISAM</em>) that solves for the transport of neutral and charged particles from the chromosphere to the corona. We investigate the effect of different mechanisms that could produce the First Ionization Potential (FIP) effect. We compare the effects of the thermal force and of the ponderomotive force. The propagation, reflection and dissipation of Alfvén waves is solved using two distinct models, the first one from <em>Chandran et al. (2011)</em> and the second one that is a more sophisticated turbulence model called <em>Shell-ATM</em>. <em>ISAM</em> solves a set of 16-moment transport equations for both neutrals and charged particles. Protons and heavy ions are heated by Alfvén waves, which then heat up the electrons via collision processes. We show preliminary results on composition distribution along a typical coronal loop and compare with typical FIP biases. This work was funded by the European Research Council through the project SLOW_SOURCE - DLV-819189.</p>

Atomic Concealment Due to Loss of Coherence of the Incident Beam of Projectiles in Collision Processes

In the study of collision processes, a series of conditions is usually assumed. One of them is that the beam of projectiles is coherent in lengths greater than those of the targets against which it strikes. However, recent experimental results and theoretical analyzes have shown that this assumption can not only fail, but that it is possible to manipulate the coherence length experimentally to go from a coherent situation to an incoherent one. The most conspicuous and studied manifestation of such loss of coherence is the disappearance of interference effects. However, in the present work we show that a strong decrease can also occur in the magnitude of the cross section, not only differential but also total, due to an atomic concealment effect.

Enzyme Kinetics Study for Heterogeneous System of Pretreated Kenaf Hydrolysis

The peculiarity of spatially restricted diffusion and molecular collision processes results in considerable contrast in a reaction between the reactant and catalyst in the heterogeneous system from its corresponding homogeneous structure. The identification of the enzymatic hydrolysis process of pre-treated kenaf and to convert it into simple sugars employing a systematic kinetic investigation is the aims of this study. The influence of substrate concentration on xylanase hydrolysis was performed in water bath shakers. In-house recombinant xylanase expressed in Pichia pastoris was used for the hydrolysis at pH 4.0 in 50 mM sodium citrate buffer with 200 rpm agitation. Modified Prout-Tompkins equation was used for the heterogeneous substrate hydrolysis. The results obtained show that temperature simultaneously influenced the time dependency of the reducing sugar yield. Dependence of the enzymatic rate of reaction can be calculated effectively on the conversion of substrates over different temperatures. The activation energy needed for pretreated kenaf hydrolysis was among the least compared to other lignocelluloses, which was only 25.15 kJ/mol. In conclusion, the exponential kinetic equation by the Modified Prout-Tompkins equation offers a solid understanding of xylanase hydrolysis on the pretreated kenaf. Thus, the prediction of the degree of hydrolysis required at the predetermined temperature and time values used can be quickly and precisely determined.