The geometric-quadratic index (GQ) is a recently introduced degree-based topological descriptor, and Kumar et al. observed that it is potentially a very good molecular descriptor. In this thesis, we characterize the extremal (chemical) graphs and trees with respect to (GQ) for a given order and size. Then, the n-vertex trees, unicyclic and bicyclic graphs with the first, second, third, fourth, fifth, and sixth maximum values of this geometric-quadratic index are determined.  

AbstractThe process of fission is oneof the oldest topics of nuclear physics that has been of interest since thepast. In the process of fission, various topics are studied. One of thesetopics is the kinetic energy of fission fragments. When the nucleus breaks,fission fragments are created, which are separated due to Coulomb repulsion andhave kinetic energy. In this thesis, using the transition state model andconcepts of the Fermi gas model, as well as considering the potential aroundthe saddle point as a parabola, the dependence of the average total kineticenergy of the fission fragments on the excitation energy of the compoundnucleus is investigated. For neutron-induced fission of 238U, 235U,233U, 239Pu, 232Th and 237Npnuclei, for which the experimental results related to total kinetic energy areavailable, we have compared theoretical calculations with the experimentalresults. The obtained results for the mentioned systems show that this.theoretical model can reproduce the experimental data well.  

  Abstract: Einstein's field equations predict the existence of four-dimensional black holes. The first uncharged and charged four-dimensional black hole solutions are known as Schwarzschild and Riesenordstrom black holes, respectively. The first three-dimensional black hole solution known as BTZ (Banados-Teitelboim-Zanelli) black holes was obtained in 1992 by solving the field equations in the presence of the negative cosmological constant. In the first part of this thesis, we obtained three-dimensional black hole solutions, with spherical symmetry, in Einstein's gravity, and after calculating thermodynamic quantities, we show that the first law of thermodynamics is true for these black holes. Then, using the canonical ensemble method, we check the thermodynamic stability of these black holes. In the second part, we extend the above idea to dilaton black holes (in Einstein-dilaton gravity). For this purpose, we obtain the black hole solutions of the field equations in the presence of a scalar field and considering the Lagrangian of the electromagnetic field as a material field and examine their geometric properties. Then we calculate the thermodynamic parameters of these black holes (mass, electric charge, temperature, entropy and electric potential) in appropriate ways. We show that the obtained quantities apply to the first law of thermodynamics of black holes and at the end we analyze the thermodynamic stability of dilatonic black holes using the canonical ensemble method. Keywords: 3D black holes, linear electrodynamics, Einstein-dilaton gravity, dilaton black holes, coupled gravity.

   In this treatise,we investigate the unpolarized transverse momentum dependent (TMD) structure of light nuclei in the modified chiral quark exchange model (QEM), for the first time. To this end, we calculate the TMD quark and gluon distributions inside the bound state nucleons of the light nuclei based on the modified chiral quark model (cQM) in which the TMD bare quark distributions of the bounded nucleons are needed. In order to compute these bare distributions, we first obtain the bare quark momentum densities using the QEM and then calculate the TMD bare distributions applying a theoretical method in which the light-cone variables are used. Finally, considering the nucleon structure of helium, tritium and deuteron nuclei, we obtain their TMD quark and gluon densities at low Q2 scale. Finally, considering the nucleon structure of   14N - 12C -4He - 6Li   uclei, we obtain their TMD quark and gluon densities at low Q2 scale. Due to the unavailability of experimental results for such nuclei, we have examined the general behavior of the obtained distributions. It is shown that our results have appropriate properties that are expected for the TMD distribution functions. Keywords: EMC effect, chiral quark model, quark exchange model, transverse momentum, light nuclei      

D* meson in the non-relativistic state in the proton-proton collision at the energy of the center of mass ?S=7Tev through the fragmentation of heavy quarks and using the factorization theorem based on the QCD theory of disturbance in hadron colliders We have studied LHC. In this case, after the proton-proton collision,quark c emitted a gluon with spin one and created a quark-antiquark pair, and the desired meson is created from the combination of heavy quark and antiquark. In the first step, calculate the function and the probability of fragmentation for quark c and b in the initial scale of fragmentation. Then, by applying the factorization theorem, we have calculated the differential cross-sectional and the total cross-sectional of ??the production of these particles. And finally, we have studied the behavior of the differential pt

   Entropy actually expresses the order of the system. We want to get the entropy for the neutron. If we consider the neutron in a non-disordered state (we consider the neutron to be composed of valence quarks), the maximum entropy is obtained from the distribution functions of valence quarks, but in the disordered state and small x, the gluon contribution is dominant, and the entropy is from the gluon distribution function Obtained. We get the entropy in the zeroth and first order of disorder. We can see that as Q2   increases, entropy increases. Then we compare the obtained entropies with the laboratory data in some specific Q2 and observe that the obtained entropy is in good agreement with the laboratory data.   

In this thesis, we have intended, to study the frequency behavior of electromagnetic wave absorption of armchair nanoribbon. for describing of the electron dynamics, we have exploited the Hubbard model Hamiltonian. In fact the electronic band structure has been obtained using Hubbard model Hamiltonian. In this model Hamiltonian, a repulsive coulomb interaction between electrons is considered in addition to kinetic energy and attractive coulomb interaction between electrons and atoms. Based on mean field approximation method, one can obtain electronic energy levels in this structure and by using that the behavior of density of states has been analysed. kubo formulation has been used for expressing electromagnetic wave absorption rate in terms of correlation function between current operatous. Finally, the relation of electromagnetic wave absorption is obtained based on band structure spectrum, after required numerical calculation, one can find the numerical values dependence of absorption spectrum in terms of waves. In the following we have studied the effects of electron?electron interaction on the electromagnetic wave absorption behavior in terms of frequency. Also the effect of nanoribbon width and electron concentration on frequency peaks of electromagnetic spectrum by the armchair nanoribbon has been investigated.

   The three approach to relativistic generalization of coherent state are discussed in the simplest case of a spinless   article: the standard, canonical, coherent states, the Lorentzian state and the coherent state introduced by Kaiser and independently by Twareque Ali,Antoine and Gazeau. All treatment utilize the Newton-Wigner localization avd dynamics described by saltpeter equation .The behavior of expectation values of relativistic observables in coherent state is analyzed in detail and the Heisenberg uncertainty relation are investigated.

  AbstractObjective: The most effective way to summarize what we know about a complex system is to identify the potential impact effects of the interaction on that system, so it is essential to examine the potential effects of the interaction in real systems. On the other hand, in the last few decades, we have witnessed a revolution in the world that has been made by science and technology in connection with two-dimensional, one-dimensional and zero-dimensional nanostructured materials. The main context of the attractive and valuable phenomena of quantum structures is quantum confinement and confinement, and therefore research on the origin and effect of confinement in quantum dots has become one of the most basic and exciting introductory fields in modern science. The aim of this study is to study meson systems in quantum dots.Research Methodology: This research is fundamental in terms of type. Due to the confinement of a quark  under the potential of , along with a suitable boundary condition, the corresponding Schrodinger equation is obtained by approximating the effective mass (EMA). For the basic state, the solution and the energy of the base state, the wave function and the probability of the quark probability are obtained. Due to the similarity of mesonic systems to electron-hole system  and also due to the choice of potential parameter approach that has flexibility, this information is compared with quantum dots consisting of electrons and holes.Results: From the phenomenological analysis, it was observed that the assumption for the effective potential of , with a certain range of values "??

The non-exclusive cross-sectional area of bifurcations was measured in ALEPH, OPAL and DELPHI experiments. in thisنامهInterpretation Using these cross-sections, the bifurcation functions of these baryons are determined by fitting to the experimental data.  

We study the damping of longitudinaloscillations of a prominence thread caused by the mass accretion.Wesuggested asimple modeldescribing this phenomenon. In this model we considered a thincurved magnetictube filled with the plasma. The prominence threadis in thecentral part of the tube and it consists of densecold plasma. The parts of thetube at the two sides of the thread are filledwith hot rarefied plasma. Weassume that there are flows of rarefied plasma toward the thread caused by theplasma evaporation at themagnetic tube footpoints. Our main assumption is thatthe hot plasma is instantaneously accommodated bythe thread when it arrivesatthe thread, and its temperature and density become equal to those of thethread. Then we derive the system of ordinary differentialequations describingthe thread dynamics. We solve this system of ordinary differential equations intwo particular cases. In the firstcase we assume that the magnetic tube iscomposed of an arc of a circle with two straight lines attached to its endssuch that the wholecurve is smooth. A very important property of this model isthat the equations describing the thread oscillations are linear foranyoscillation amplitude. We obtain the analytical solution of the governingequations. Then we obtain the analytical expressions for theoscillation dampingtime and periods. We find that the damping time is inversely proportional tothe accretion rate. The oscillationperiods increase with time.We conclude thatthe oscillations can damp in a few periods if the inclination angle is sufficientlysmall, notlarger that 10° , and the flow speed is sufficiently large, notless that 30 kms-1 . In the second model we consider the tube withthe shapeof an arc of a circle. The thread oscillates with the pendulumfrequency dependent exclusively on the radius of curvature of the arc.Thedamping depends on the mass accretion rate and the initial mass of the threathatis the mass of the thread at the moment whenit is perturbed. First we considersmall amplitude oscillations and use the linear description.

   this thesis, the production of mesons and electron-positron destruction at the Z0 pole is studied. Therefore, using quadratic quadratic quenching functions with pQCD, first, the disturbance is calculated. Then the branching ratios and the states with its longitudinal and transverse polarization are calculated. We also compute the decay rates for the mesons, namely (? (Z ^ 0 ? B_s ^ * X)) / ?_tot and its longitudinal and transverse polarization modes. Therefore, we calculated the surface area of the production of these mesons around the pole in the DEPHI experiment.

  in this article We investigate the structure of the light nuclei based on the modified chiral quark model (?QM. To this end, we first calculate the parton distribution functions (PDFs) of the bounded nucleons using the ?QM and then compute those of the light nuclei. For this purpose, it is first needed to obtain the bare quark densities inside the bounded nucleons of the nucleus. These bare distributions are calculated by applying the quark exchange model (QEM) in this article. Finally, we obtain the quark, antiquark, and gluon distributions and also the structure functions (SFs) of the bound state nucleons and the light nuclei at low Q2 scale (Q2 = 0.35 GeV2). These distributions can be evolved to the higher scales using DGLAP evolution equations. It is shown that the results of our theoretical framework are in good agreement with the experimental data

  It is thought that the internal structure of free nucleons with internal structure of bound nucleons inside the nucleus is the same. In 1362/1983 the research group EMC,using muon deep inelastic scattering experiment the nuclei, measured ratio of the iron nuclei structure functions to the deuteron nuclei structure function in nucleon unit, that on the contrary expectation is not one. This phenomenon is known as EMC effect that the indicates that the components distribution of   bound nucleus is different from the free nucleus. In this thesis is to investigate the quark exchange model and this model shows that in the range of middle x the quarks valance may have a the share in the EMC. But this model in large and small x range is not able to explain the EMC effect. For large x range، fermi motion have a major role and for small x range، quark exchange model is not comprise role of   the sea quarks and gluons in the structure function. In this thesis, using the quark constituent   exchange model is calculate share   sea quarks and gluons in the structure functions.

  The upsilon meson has a quark structure b . This meson has a spin-1 in the S-wave state, and it is possible to generate in the electron-positron annihilation. In this thesis, the direct production of upsilon was investigated by direct quark and anti-quark b and gluon fragmentation. Accordingly, considering the Fermi motion corrections and NLO corrections, the meson-upsilon cross section production is calculated around its mass and around the Z0 pole. The results are in good agreement with experimental data. Additionally, the Z0 decay rate has been calculated for the upsilon meson, taking into account the Fermi motion corrections and NLO corrections.

   چكيده    روش اكتشافي SP يا پتانسيل خودزا از جمله روش هاي اكتشافي در ژئوفيزيك كاربردي با چشمه طبيعي است و اساس آن بر اندازه گيري اختلاف پتانسيل الكتريكي حاصل از فعل و انفعالات الكتروشيميايي، ترموالكتروشيمايي و الكتروسينتيكي، كه بين توده هاي معدني و الكتروليت هاي محيط زير سطحي اتفاق مي افتد، استوار است. در مدل سازي هاي صورت گرفته در دهه هاي اخير سعي بر آن بوده تا اين بي هنجاري هاي SP به اشكال هندسي خاصي مانند كره، استوانه و ورقه تقريب زده شده و با روش هاي عددي مانند مدل سازي معكوس و بهره گيري از روش كاهش مربعات خطاها، پارامترهاي توده معدني   مانند عمق(Z) ، زاويه قطبيدگي ( ) و گشتاور دو قطبي الكتريكي ( K ) تخمين زده شود. در اين تحقيق از شبكه عصبي پرسپترون چند لايه (MLP )با ميانگين مربعات خطاي(MSE)برابر با 0001. به منظور تخمين شكل هندسي بي هنجاري و محاسبه پارامترهاي توده معدني به ويژه در رابطه با استوانه افقي و قائم در مناطقي مانند جفرسون ايالات متحده، باوارياي آلمان و سرير تركيه استفاده شده و نتايج آن با نتايج به دست آمده از ديگر روش هاي تفسير مقايسه شده است.

  In this thesis, the data collected using a Schlumberger method in the Ziaabad village of Markazi province have been used to reverse one-dimensional and two-dimensional of the special resistance, and the actual special resistance sections from one-dimensional and two-dimensional modeling have been compared. The goals of this research are how to process and model data and make optimal interpretations of subsurface structures and groundwater in the region. In this thesis, using the Schlumberger array, the special resistivity data obtained from field measurements using one-dimensional and two-dimensional reversal methods using the ZondRes2D software was performed using this geoelectric software for each of the profiles, as well as the special resistance maps for different electrode distances are plotted by Geo- soft software. Finally, using the results of data reversal, comparing the resistive cross sections in one-dimensional and two-dimensional mode, and the best location for water exploration in the region is proposed. Geophysical studies were carried out using a vertical electric catheter method with a distance of 500 m and the distance between the electrodes of flow A and B is 600 meters. The number of measured soondage is 39 in line with 5 geoelectric profiles (A-B-C-D-E). From geostationary explanations, we find that the depth of the juice layer is low and the bedrock is firm and close to the surface. The best location for drilling wells is initially the distance between the explorations 7 to 37 with the coordinates of 368272- 3844064 and then in the second priority In the distance between the catacombs 35 to 36 with the coordinates of 388262- 3844488, it is necessary to dig a well to a depth of about 120 meters.. In this thesis, the data collected using a slowness method in the Ziaabad village of Markazi province have been used to reverse one-dimensional and two-dimensional strength of the special strength, and the actual special resistance sections from one-dimensional and two-dimensional modeling have been compared. The goals of this research are how to process and model data and make optimal interpretations of subsurface structures and groundwater in the region. In this thesis, using the flare array, the special resistivity data obtained from field measurements using one-dimensional and two-dimensional reversal methods using the ZondRes2D software was performed using this geoelectric software for each of the profiles, as well as the special resistance maps for Different electrode distances are plotted by geospatial software. Finally, using the results of data reversal, comparing the resistive cross sections in one-dimensional and two-dimensional mode, and the best location for water exploration in the region is proposed. Geophysical studies were carried out using a vertical electric soondage method with a distance of 500 m and the distance between the electrodes of flow A and B is 600 meters. The number of measured soondage is 39 in line with 5 geoelectric profiles (A-B-C-D-E). From geostationary explanations, we find that the depth of the juice layer is low and the bedrock is firm and close to the surface. The best location for drilling wells is initially the distance between the explorations 7 to 37 with the coordinates of 368272- 3844064 and then in the second priority In the distance between the catacombs 35 to 36 with the coordinates of 388262- 3844488, it is necessary to dig a well to a depth of about 120 meters.

Investigate of the weak contribution of nucleon structure functions 

  Using effective liquid drop model, we studied the proton radioactivity and alpha decay of some neutron deficient nuclei. For these nuclei the experimental half- lives are available. The purpose of this thesis is to calculate the half-lives of these decays based on the effective liquid drop model and competition between them. For som isotopes Ir and Au, the variations of half-lifves of these decays are plotted in terms of the neutron number. Also, for the proton radioactivity, we have obtained the variation of the reduced half-lives with Coulomb parameter. The reduced half-lives logarithm has a linear relation ship with this parameter. The obtained results of this model show that there is a good agreement between the experimental and theoretical results for the half-lives of the proton and alpha decay. Also, the dominant decay mode predicated by this model is in a agreement with the experimental results.

  Abstract   Operational algebra method means the technique of applying ladder operators to obtain spectra   of eigenvalues energy and wave eigenfunctions corresponding to quantum mechanical operators that are widely used in educational books related to solving the equation of momentum and harmonic oscillator Is taken. Dirac first devised these operators and was able to use this method to analyze angular momentum and to show that the quantum number of the total angular momentum should be a half-integer multiplicity of Planck's constant.        There are several advantages to using this method in contrast to the old method of solving the second-order differential equation but this technique involves employing ladder operators for the radial equation of the hydrogenlike atom is not found as an important model in books and research papers related to quantum physics; instead, only an analytical method with the series-solution method is used. In this new method, first by constructing a commutative operators set, we create the Hilbert space associated with it, which is the same space of the system's state, and then, by creating a linear combination of the non-commutative operators system set, we define the increasing and decreasing operators. In this new research based on the nature of wave mechanics, the operational algebra method is used to solve the Schr?dinger equation for the hydrogenlike atom system, whith similar functions to the previous models in the effect of ladder operators on quantum states of the system, energy quantization and the orthonormal wave eigenfunctions Will be produced quite accurately and without any arbitrary assumptions.

  In this thesis, first, we look at the theory of quantum fields especially the quantum fields of the spinor and vector, in the first and second chapters them we describe the general definition of coherent states and their properties.In the third chapter, we state which the definition of Fourier transform, the Fourier transform is the oldest signal conversion tool that decomposes a signal into components of exponential functions with different frequencies and it is able to transmit the received signal from the time domain to the frequency domain. This conversion lacks any information about the time of each frequency occurrence. In other words, in this transformation, the time dependent information is completely eliminated. [1]In fact, depiction of signal in the frequency domain, do not have efficiency for analysis of non-static signals; because of the inability to represent frequency variations over time. As the result, we find that there is a need of distribution with the ability to represent frequency variations over time, that it shows time-frequency distributions as well as these signal variations. [2] We have stated them in chapter four. Gabor only used the Fourier transform for the short time limit from receiving signal, with the invention of a new method, and he called this time limit as the time window.Gabor, calculated the Fourier transform of each part by moving the window over the time of receiving signals and he called it the Fourier transform, that it is an example of time-frequency analysis. This conversion has the fixed width of window simultaneously, that leads to non- >In the fifth chapter, we scrutinized the basis implement of MRI, which is based on the spin motion of the nuclei of the hydrogen atom, then we describe the methods of imaging, including spin-echo, multidimensional imaging, multi-image imaging, and so on. Also, In Chapter 6, we have explained the components of the MRI machine in details.

The depth of investigation in geophysical methods has the great importance. It is very important to know how much of the ground can be detected by measurments . The depth of investigation (DI) in electromagnetic (EM) sounding is a maximum depth at which a given target in a given host can be detected by a given sensor. Depth of investigation is determined compeletly empirical and the factors which affect the depth of investigation are the dimensions of the given AEM system (coil configuration,coil separation, frequency); the signal (S) and noise (N) levels of the system; properties of the conductive subsurface such as conductors geometry; size, position; conductivity values of the host rock, overburden, and the conductor itself and   the teckniques used in data processing and interpretation. In this thesis the depth of investigation for frequency-domain airborne electromagnetic sensor is investigated. The main purpose of this study is theoretically calculation of the relationship between depth of investigation and factors affected. simple relations are calculated for the DI over layered half-space models using airborne electromagnetic sensors based on analysis of measured data so that before costing for drilling and exploiting, an approximation of the depth of investigation can be estimated. Results show that the depth of investigation increases if: the skin depth increases the threshold value decreases, the separation distance increases   and the resistivity contrast between host rock and target increases.  

As physicists, we want to understand how nature works. Therefore no matter what we calculate, eventually it has to agree with observations. If we want to claim we understand how particles interact with each other eventually we have to link our understanding to quantities that can be measured in experiments. This work has tried to explain some aspects of one of the means that particles can interact, which is via the strong interaction. This leads to many interesting effects but it can make it difficult to study in some regimes. In recent years moving together to provide results at strong coupling. String theory in AdS space is a great tool for studing non-perturbative aspects of QCD. According to AdS/CFT correspondence gravity theory in (d+1)-dim in AdS space is dual to a conformal theory in the d-dim boundary. So machinery of AdS/CFT can be applied to QCD, but QCD is not conformal and gravity dual to QCD is not known yet. Deep inelastic lepton-nucleon scattering (DIS) and Pomeron dynamics and structure functions is investigated at small x in the frame work of holographic quantum chromodynamics. Finally we study the dual scattering amplitude of 2? 2 scattering of hadrons through the exchange of a spin j field. The parameter length string   is fixed by requiring cross sectio   to have pomeron-like behavior   and   pomeron-like intercept.     Key Words: AdS/QCD duality, AdS/CFT correspondence, hard & soft wall model, pomeron exchange  

  The Effect of Zagros Mountain Range on the Dust storm

supersymmetry 

 quarkonium production

بررسي ويژگي هاي الكترونيكي پليمرها

The alpha decay half-lives of superheavy nuclei (SHN) are investigated by employing a unified fission model (UFM) and Royer’s analytical formula .The good agreement with the experimental data indicates the UFM and the analytical formula are useful tools to investigate these ?-decays. A modified formula is proposed for determining the spontaneous fission half-lives based on Swiatecki’s formula. The spontaneous fission half lives for heavy and SHN in regions from Th to Fl are calculated systematically. Experimental data are well reproduced by the modified Swiatecki formula. The competition between ? decay and spontaneous fission is analyzed in detail and the decay modes are predicted for the unknown cases.

  Internal solitons generated at the Columbia River plume front during ebb tides are revealed in Synthetic Aperture Radar (SAR) images. Scale analyses indicated that these internal waves belong to the finite-depth category. Based on the study by Zheng et al. [2002], a theoretical model for the finite-depth category was developed that relates radar backscatter cross-section to dynamic parameters of internal solitons. Using the theoretical model and in-situ density data collected by the River Influences on Shelf Ecosystem (RISE) project cruise in July 2004, we obtained the half width, amplitude, phase speed, and wave energy per crest length of the internal solitons at four.

  We have investigated the effect of thermal conduction and compressive viscosity on the damping of longitudinal magnetohydrodynamic waves generated in a cooling background in a uniformly magnetised plasma. Compressive viscosity and thermal conduction are assumed to be the dominant mechanisms for the damping of the oscillations in hot coronal loops. We have assumed the low-beta plasma to use the rigid flux tube approximation, which enables us to disregard the magnetic field perturbation therefore the magnetic field was assumed to be constant and aligned along the z-direction. The background temperature is allowed to change as a function of time and to decay exponentially with characteristic cooling times typical for coronal loops which is much longer than the characteristic oscillation period P, i.e., that we consider a temporally slowly varying plasma. The latter assumption has allowed us to use the WKB method to model the damped oscillations. In the leading order approximation of the WKB method, called the approximation of geometrical optics, we have derived the dispersion equation determining the instantaneous complex frequency of the loop oscillation. In the next order approximation, called the approximation of physical optics, we have obtained the equation determining the variation of oscillation amplitude with time.   We have used the analytical results to estimate the dependence of the oscillation amplitude on time numerically. We have obtained in cold loops the damping due to compressive viscosity is very weak and in hott loops the damping of oscillation becomes stronger also, cooling reduces the damping rate due to compressive viscosity. But in loops with higher temperature, taking into account the effects of compressive viscosity and thermal conduction can overcome the effect of cooling and the oscillation amplitude secreases with time in cooling coronal loops.

    nteractions of baryons containing two heavy quarks spectroscopy and light quark and a heavy quark mass approaches infinity, so that will be very simple, and that is because of heavy quarks, heavy diquark smaller than a length scale of this allowed us to have strong interactions that the color of the perturbation theory of quantum mechanics to calculate the fragmentation functions of these heavy baryons .in oneering heavy fragmentation functions include quarks b nd c baryons in the quark  - diquark model

 In this thesis, zohdys method which was firstly applied, as a quick method, to interpret geoelectrical Schlumberger and Wenner data, is used to invert frequency domain airborne electromagnetic (AEM) data. This method is based on a layered earth and without having an initial guess, the number thickness and conductivity of the ground can be calculated. Basically, this method is a kind of forward modelling in which the starting model is created from data itself. Then this model changes in thickness and conductivity of layers so that the difference between observed data and calculated data from changing model reaches to a minimum. Now, the model of the earth is founded. This method is applied on airborne electromagnetic (AEM) data from one and two dimensional synthetic multi-layer models and the result show that zohdys method has acceptable performance to retrieve conductivity and thickness values of earth layers.

همجوشي هسته اي از طريق كاتاليزور   ميوني يكي   از روش هاي انجام   همجوشي براي توليد   انرژي است. اين روش به دليل انجام شدن در دماي محيط و عدم توليد پسماند هاي راديواكتيو مضر، در سال هاي اخير مورد توجه قرار گرفته است. در اين پايان نامه ما با استفاده از روش برنامه نويسي فرترن به حل معادلات ديناميكي پرداختيم و بازده كاتاليزور ميوني را براي سيستم هاي D-T و H-D-Tدر شرايط جامد و مايع محاسبه نموده ايم و شرايط بهينه براي انجام همجوشي را   به دست آورده ايم. هم چنين   مشاهده كرديم كه با افزايش   غلظت تريتيم، بازده كاتاليزور ميوني در سيستم   H-D-T افزايش مي يابد، در حاليكه در سيستم D-Tيك قله در نمودار ديده مي شود. اما با افزايش چگالي   محيط، بازده در هر دو   سيستم افزايش مي يابد. هم چنين آهنگ   چرخه ي ميون، طيف زماني نوترون هاي حاصل از   همجوشي و ضريب چسبندگي مؤثر سيستم ها را نيز محاسبه نموده ايم. در انتها نيز اثر اسپين بر بازده همجوشي كاتاليزور ميوني بررسي كرده ايم و مشاهده كرديم كه با وارد كردن اسپين در معادلات ديناميكي، بازده همجوشي اندكي كاهش مي يابد.

پس از آزمايش ناكشسان عميق الكترون پروتون SLAC] در سال 1969 تلاش هاي زيادي توسط دانشمندان نظري و تجربي براي بدست آوردن اطلاعات بيشتر در مورد ساختار پارتون­ها [2]   يعني كوارك­هاي ظرفيت، كوارك­هاي دريا و گلئون­ها مربوط به هادرون­  hy;ها و هسته انجام شده است. در بخش تجربي اولين مشاهده در سال 1983 توسط گروه EMC[3] بود. آنها مشاهده كردند كه هنگامي كه هدف از دوتريم به هسته­ي ­سنگين تغيير داده شود اثر قابل توجهي در توابع ساختار نوكلئون­ها ظاهر مي­شود. اما در سال ­هاي اخير بسياري از آزمايش­ها مطالعه­ي خود را روي توابع ساختار هادرون­ها (عمدتا پروتون ونوترون) در xهاي(xمتغير مقياس بيوركن است[4] (كوچك متمركز كرده­اند كه در آنجا كوارك­هاي دريا و گلئون­ها نقش مهمي را بازي مي­كنند. در سال­هاي اخير هم, استفاده از هدف­هاي هليوم سه و تريتيوم غيرقطبيده براي پرتوهاي با انرژي GeV 11 آزمايشگاه جفرسون فراهم شده است . به منظور محاسبه تابع ساختار نوترون از نسبت تابع ساختار هليوم سه و تريتيوم استفاده مي­شود چون، برخلاف پروتون تابع ساختار نوترون را نمي­توان به صورت مستقيم مورد مطالعه قرار داد، بنابراين بايد تابع ساختار آنرا به شيوه­ي غير مستقيم استخراج كنيم. در سال 1986جفي و هدبوي[5] با استفاده از پراكندگي ناكشسان ژرف نسبت تابع ساختار پروتون يا نوترون را در حالت مقيد و آزاد را محاسبه كردند اين انتظار وجود داشت كه، نسبت تابع ساختار حالت مقيد به حالت آزاد برابر يك باشد اما با مشاهده نتايج تجربي و نتايج تئوري و مقايسه آنها ديده شد كه اين نسبت يك نيست. بنابراين به دنبال توجيه اين اختلاف با ارائه مدل­ها و روش­هاي نظري بودند. دلايل مختلفي براي اين تغيير توزيع كواركي داخل نوكلئون­هاي مقيد و آزاد بيان شد كه از جمله مي­توان به اثر فرمي، اثر انرژي بستگي و اثر تبادل كواركي اشاره كرد. در اين پايان نامه بر آن هستيم تا با استفاده از مدل كوارك سازنده سهم كوارك­هاي دريا و گلئون­ها را در توابع ساختار نوكلئون­ها اعمال نموده و انتظار مي­رود كه نتايج اين محاسبات با داده­هاي تجربي به ويژه با داده­هايي كه از آزمايشگاه سرن و جفرسون كه در سال­هاي اخير بدست آمده­اند هم­خواني بهتري داشته باشند.     

در اين پايان نامه پس از مقدمه ي مختصر بر پراكندگي هاي كشسان و ناكشسان رابطه اي براي سطح مقطع ديفرانسيلي پراكندگي ناكشسان الكترون پروتون بدست مي آيد وسپس مدل پارتون و رابطه ي اصلي اين مدل يعني رابطه ي كالان گراس بدست مي آيد اين رابطه به ما اجازه مي دهد كه ر صورت داشتن توابع توزيع پارتون هاي درون نوكلئون بتوان به توابع ساختار آنها دست يافت .

In decays of the Z0, the dominant mechanism for the direct production of charmonium states is the decays of the Z0 into a pair heavy   anti quark b or c followed by its fragmentation into the charmoniom and butmoniom states. First we calculate the fragmentation functions describing the splitting of   heavy anti quarks into S-wave quarkonium states to leading order in the QCD coupling costant. We use our   fragmentation functions to calculate the production rate of heavy quarkonium states in Z0 decay and   so decay rate of Z0 to the pair heavy quark   cc ,bb.       PACS No.13

This thesis describes azimuthal dependence of heavy quark initiated contributions to the lepton-nucleon deep inelastic scattering (DIS). In general, in recent decades, investigation of heavy quark production is of particular interest and the activities that accomplished in different collaborations express significance of this matter. In this work, since the sources of the production of heavy quark is different relative to the kind of colliding particles, we propose different reactions leading to the production of heavy quarks and finally limit our study to production of heavy quark in lepton-nucleon DIS. For this reason, first we investigate deep inelastic electron-proton scattering and define the cross section of this process, then we write the relations between parton-level semi-inclusive structure functions and the helicity   cross sections in terms of arbitrary values of heavy quark mass. Then the azimuth-dependant   lepton-quark DIS in helicity basis has been calculated. Finally, we investigate the numerical properties of   and   distributions caused by photon-quark scattering (QS) contribution. We conclude that contrary to the photon-gluon fusion (GF) component, the QS mechanism practically is -independant. This fact implies that measuring azimuthal distributions in these processes directly can probe the heavy quark inside the proton. Our results indicate that the GF and QS predictions for   asymmetries are quantitatively well defined in fixed flavor number scheme (FFNS): they are stable, both parametrically and perterbatively.   

  در اين پايان­نامه ما در ابتدا به معرفي پروژه برخورددهنده بزرگ هادرون-الكتروني پرداخته و سپس با معرفي مدل استاندارد فيزيك ذرات و جدول ذرات بنيادي، در مورد اهميت و خواص و نيز نحوه توليد كوارك سر به عنوان سنگين­ترين ذره بنيادي شناخته شده در طبيعت با استفاده از نتايج آزمايشگاهي صحبت خواهيم كرد. در محاسبات نظري، كوارك سر به دليل جفت شدگي بسيار زيادي كه با بوزون هيگز دارد مورد بسيار خوبي جهت تحقيق در حيطه فيزيك هيگز مي­باشد. به همين دليل در اين كار ما به جستجو و تعيين سطح مقطع براي جفت شدگي كوارك-پادكوارك سر و بوزن هيگز در فرآيند پراكندگي ناكشسان عميق الكترون-پروتون در برخورددهنده بزرگ هادرون-الكتروني پرداختيم. فرآيند مورد نظر ما كه از پراكندگي ناكشسان عميق بين الكترون و پروتون سر چشمه مي­گيرد، به وسيله فوتون مجازي منتشر شده از الكترون و نيز گلوئون ساتع شده از پروتون انجام مي­شود كه به اين فرآيند همجوشي بوزون-گلوئون مي­گوييم. نتيجه محاسبات ما با استفاده از پتانسيل عظيم به وجود آمده در برخورددهنده بزرگ هادرون-الكتروني مي­باشد به اين دليل كه برخورددهنده­هاي لپتون-هادروني نسل قبل انرژي لازم براي توليد اين ذره سنگين را نداشتند. در نهايت ما نتيجه بدست آمده از سطح مقطع مربوط به جفت­شدگي كوارك-پادكوارك سر و هيگز را با نتايج موجود در برخوردهاي هادرون-هادروني و همجوشي گلوئون-گلوئون مقايسه كرده و بيان مي­كنيم كه هرچند سطح مقطع اين فرآيند از طريق همجوشي بوزون-گلوئون كمتر است اما دقت محاسبات براي شناخت فيزيك هيگز بسيار دقيق­تر خواهد بود.

In this thesis first we are talking about Deep inelastic scattering and Parton model. In short study nuclear model and effect to change parton distribution in nuclei. Then we come to the parton distribution evolution equations, DGLAP, and how to solve it. Here we solve the equation in the approximation DLL. Finally, with the help of a weight factor obtain nuclear Parton distribution functions from a single nucleon Parton distribution functions (related to experimental measurements).Result of study nuclear distribution function show the nuclear effect such as: Shadowing in low x and EMC and anti Shadowing in high x.