75 research outputs found
Thermal QCD Sum Rules Study of Vector Charmonium and Bottomonium States
We calculate the masses and leptonic decay constants of the heavy vector
quarkonia, and mesons at finite temperature. In particular,
considering the thermal spectral density as well as additional operators coming
up at finite temperature, the thermal QCD sum rules are acquired. Our numerical
calculations demonstrate that the masses and decay constants are insensitive to
the variation of temperature up to , however after this point,
they start to fall altering the temperature. At deconfinement temperature, the
decay constants attain roughly to 45% of their vacuum values, while the masses
are diminished about 12%, and 2.5% for and states,
respectively. The obtained results at zero temperature are in good consistency
with the existing experimental data as well as predictions of the other
nonperturbative models. Considerable decreasing in the values of the decay
constants can be considered as a sign of the quark gluon plasma phase
transition.Comment: 14 Pages, 8 Figures and 2 Table
Thermal modifications of the heavy axial vector mesons properties
Azizi, Kazem (Dogus Author) -- Conference full title: 10th Conference on Quark Confinement and the Hadron Spectrum, Confinement 2012; Munich; Germany; 8 October 2012 through 12 October 2012We investigate the properties of the heavy axial vector χb1 and χc1 quarkonia at finite temperature. Taking into account the thermal spectral density as well as additional operators coming up at finite temperature and perturbative two-loop order corrections to the correlation function, we obtained the thermal QCD sum rules for considering particles. It is observed that the masses and decay constants almost remain unchanged with respect to the variation of the temperature up to T ≈ 100MeV, however after this point, the decay constants decrease sharply and approach approximately to zero at critical temperature. This situation may be interpreted as a signal for deconfinement phase transition and our results at zero temperature are in good consistency with the existing experimental values
Thermal properties of the heavy axial vector quarkonia
Using the additional operators coming up at finite temperature, we calculate the masses and decay constants of the P wave heavy axial-vector chi(b1) and chi(c1) quarkonia in the framework of thermal QCD sum rules. In the calculations, we take into account the perturbative two loop order alpha(s) corrections and nonperturbative effects up to the dimension four condensates. It is observed that the masses and decay constants almost remain unchanged with respect to the variation of the temperature up to T similar or equal to 100 MeV, however after this point, the decay constants decrease sharply and approach approximately to zero at critical temperature. The decreasing in values of the masses is also considerable after T similar or equal to 100 MeV
Mesons spectral functions at finite temperature
Azizi, Kazem (Dogus Author) -- It was firstly submitted to 3rd International Conference on Hadron Physics, TROIA'11.We investigate the thermal spectral densities for (pseudo)scalar and vector currents in the framework of the real time formalism when mass of two quarks are different. Such spectral densities are necessary for the phenomenological investigation of in-medium properties of hadrons. We use the quark propagator at finite temperature and calculate annihilation and scattering parts of spectral densities for above mentioned currents. The investigations show that the thermal contributions are significantly important. The obtained results at T 0 limit are in good consistency with the vacuum results.Ozyegin University, Middle East Technical University, Canakkale Onsekiz Mart University, HadronPhysics2 Consortium
Decay constants of heavy vector mesons at finite temperature
Azizi, Kazem (Dogus Author) -- 2nd International Conference on Particle PhysicsThis study deals with determination of the decay constants of heavy vector mesons in the framework of the thermal QCD sum rules. We calculate both thermal spectral density and non-perturbative contributions taking into account the traditionally existing operators at T = 0 and also additional operators appearing at finite temperature. Analysis of the obtained thermal sum rules shows that the decay constants almost remain unchanged with respect to the variation of temperature up to T ≅ 100 MeV, however after this point, they start to decrease sharply with increasing temperature
Landslide control in Rize Taşlıdere basin:Case studies from Kireçhane and Kırklartepe areas
Rize ilindeki orman tahribatı ve arazinin koruma-kullanma tekniği dikkate alınmadan kullanılması
il genelindeki heyelan riskini artırmaktadır. Bu çalışmanın amacı Rize Taşlıdere Havzası, Kireçhane
ve Kırklartepe yöreleri heyelan kontrolü amaçlı örnek olay incelemesidir. Bu amaçla araştırma alanı
yükselti kademelerine ayrılmış, her bir katmanda toprak penetrasyon direnci ve nem içeri ile 2. yükselti
katmanında birikimli infiltrasyon ölçümleri yapılmıştır. Ayrıca katmanlarda 0-10 ve 10-30 cm
derinliklerinden toprak örnekleri alınarak laboratuvara gönderilmiştir. Laboratuvarda tekstür ve suya
dayanıklı (SDA) analizleri yapılmıştır. Ortalama değerlere göre araştırma sahasındaki zemin biriminin
%60’ı yüksek plastisiteli kil, %40’ı ise düşük plastisiteli kil türündedir. Ortalama değerlere göre en
yüksek su doygunluk değerine en yüksek kilin (%44,44), olduğu IV. yükselti kademesinde
rastlanmıştır. Araştırma alanı III. yükselti kademesinde ölçülen birikimli infiltrasyon kapasitesindeki
değişimin zamana göre R2 = 0,988 ile y= -0,0098x2+2,5x+18,03 şeklinde ilişkiye sahip olduğu tespit
edilmiştir. Yükselti kademelerine göre en düşük penetrasyon direncine (0.03 mPa) I. yükselti
kademesinde ve 8 cm toprak derinliğinde, en yüksek penetrasyon direncine (0.112 mPa) IV. yükselti
kademesinde ve 30 cm toprak derinliğinde rastlanmıştır. Suya dayanıklı agregat (SDA) değerlerine
bakıldığında en yüksek değere I. yükselti kademesinin alt topraklarında, en düşük değere ise II. yükselti
kademesinin üst topraklarında rastlanılmıştır. Koruma-kullanma dengesine uygun toprak yönetim
modelinin oluşturulması araştırma alanı topraklarının heyelan oluşturma riskini azaltabilir.The deforestation in Rize province and the use of the land without considering the
protection-use technique increase the risk of landslides throughout the province. The aim of this study
is a case study for landslide control in Rize Taşlıdere Basin, Kireçhane and Kırklartepe regions. For
this purpose, the research area was divided into elevation levels, soil penetration resistance and
moisture content in each elevation steps, while cumulative infiltration measurements were made in the
2
nd elevation. In addition, soil samples were taken at 0-10 cm and 10-30 cm depths. Texture and water
resistance (SDA) analyzes were performed in the laboratory. According to the average values, 60% of
the soil in the study area is clay with high plasticity and 40% is clay with low plasticity. The highest
water saturation value was found at the IV altitude steps where the clay content was the highest
(%44,44). The cumulative infiltration capacity measured at the altitude III has a relationship with
R
2=0.988 and y=-0.0098x2+2.5x+18.03 according to time. According to the elevation, the lowest
penetration resistance (SPR) (0.03 mPa) was found at elevation-I and at 8 cm soil depth, while the
highest penetration resistance (0.112 mPa) at the elevation- IV and at 30 cm soil depth. The highest
water-resistant aggregate (WSA) content was measured at 10-30 cm soil depth in the elevation-I, while
the lowest WSA measured at 0-10 cm soil depth in the elevation-II. Establishing a soil management
model suitable for the protection-use balance can reduce the risk of landslide formation in the research
area
The Determination of the Effect of Cover Crop Before Sunflower Production on Seed Yield, the Application of Nitrogen Rate and Water Content in the Soil in Trakya Region
DergiPark: 245925trakyafbdTrakya koşullarında, buğday hasadından sonra ayçiçeği ekilinceye kadar olan ara dönemde toprakta yeşil örtü oluşturularak erozyonun önlenmesi ve ot üretilmesi amacıyla, Macar fiği (Vicia pannonica L.) yetiştirilmiştir. Ön bitki fiğ, yeşil ot elde etmek için, ilkbaharda Nisan ayının ikinci yarısı ve Mayıs ayının ilk yarısı olmak üzere iki faklı zamanda biçilmiştir. Baklagil yem bitkisi yetiştirilen bu sistemde ayrıca ayçiçeğine uygulanacak azot miktarını belirlemek amacıyla, alt-alt parsellere 0-5-10-15 kg/da saf azot dozları uygulanmıştır. Yapılan toprak nemi ölçümlerinde, ön bitki toprak nemini azaltmış ve kayıp nem yaz yağışlarıyla karşılanamadığı için, ayçiçeği verimini düşürmüştür. Bu verim düşüklüğü, ön bitkinin hasadı geciktikçe artış göstermiştir. Bu nedenle ön bitki hasat edilmiş parsellerden elde edilen ayçiçeği verimi, sürülü parsellere nazaran daha düşük olmuştur. Yapılan ekonomik analiz sonucuna göre; ön bitkisi olarak yetiştirilen fiğden elde edilen ot geliri; ayçiçeği verim düşüklüğünü karşılamakta ve artı gelir sağlamaktadır. Ayçiçeği parsellerine uygulanan farklı azot dozları neticesinde, azot ile verim arasında önemli bir ilişki bulunmamıştır. Buğday-ayçiçeği münavebe sistemindeki ara dönemde, ayçiçeğinden önce ön bitki yetiştirilmesi durumunda ön bitkilerin erken hasadından sonra ekilen ayçiçeklerinin verimi, geç hasat edilene nazaran daha yüksek olmuştur. Araştırma sonuçlarına göre yapılan kâr-zarar analizi sonucunda, kış dönemi yağış durumu normal olduğunda, Trakya bölgesinde ayçiçeğinden önce ön bitki olarak Macar fiği yetiştirilmesi, kârlı bir yöntem olarak bulunmuşturThe Hungarian vetch (Vicia pannonica L.) planted to prevent erosion with setting the green cover on the soil surface and to produce forages for animal feed. The cover crop was cut twice as early and late cutting in the spring. The nitrogen doses were 0-5-10-15 kg per da before sunflower planting to determine of the optimum nitrogen rate. The sunflower (Helianthus annuus L.) yield was decreased due to cover crop planting and the seed yield decreased when harvest being late. Due to soil water uses, sunflower yield was lower than ploughed plots. However; these yield losses were compensated from forage crops production with getting extra income based on economical analysis. There were no significant difference between nitrogen doses and any positive increase on seed yield in normal rainy winter season. On the other hand, high sunflower yields were obtained from early cover crop harvesting so early sunflower planting in the experiment. Based on economical analysis results of the research; cover crop planting before sunflower production in the wheat-sunflower rotation system were found as profitable method especially in rainy winter seasons in Trakya regio
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