192 research outputs found
Anomalous single production of fourth family up type quark associated with neutral gauge bosons at the LHC
From the present limits on the masses and mixings of fourth family quarks,
they are expected to have mass larger than the top quark and allow a large
range of mixing of the third family. They could also have different dynamics
than the quarks of three families of the Standard Model. The single production
of the fourth family up type quark t' has been studied via anomalous production
process pp-> t'VX (where V=g,Z,\gamma) at the LHC with the center of mass
energy of 7 and 14 TeV. The signatures of such process are discussed within
both the SM decay modes and anomalous decay modes of t' quarks. The sensitivity
to anomalous coupling kappa/Lambda=0.004 TeV^(-1) can be reached at sqrt(s)=14
TeV and L_(int)=100 pb^(-1).Comment: 15 pages, 9 figure
Pair Production of Fourth Family Charged Sleptons at Colliders
We study the pair production of , which is the supersymmetric
partner of the fourth family charged lepton, at the colliders. It
is shown that the investigation of this process at ILC/CLIC will give
opportunity to differentiate the MSSM with three and four families.Comment: 6 pages, 2 figure
Search for Top Quark FCNC Couplings in Z' Models at the LHC and CLIC
The top quark is the heaviest particle to date discovered, with a mass close
to the electroweak symmetry breaking scale. It is expected that the top quark
would be sensitive to the new physics at the TeV scale. One of the most
important aspects of the top quark physics can be the investigation of the
possible anomalous couplings. Here, we study the top quark flavor changing
neutral current (FCNC) couplings via the extra gauge boson Z' at the Large
Hadron Collider (LHC) and the Compact Linear Collider (CLIC) energies. We
calculate the total cross sections for the signal and the corresponding
Standard Model (SM) background processes. For an FCNC mixing parameter x=0.2
and the sequential Z' mass of 1 TeV, we find the single top quark FCNC
production cross sections 0.38(1.76) fb at the LHC with sqrt{s_{pp}}=7(14) TeV,
respectively. For the resonance production of sequential Z' boson and decays to
single top quark at the Compact Linear Collider (CLIC) energies, including the
initial state radiation and beamstrahlung effects, we find the cross section
27.96(0.91) fb at sqrt{s_{e^{+}e^{-}}}=1(3) TeV, respectively. We make the
analysis to investigate the parameter space (mixing-mass) through various Z'
models. It is shown that the results benefit from the flavor tagging.Comment: 20 pages, 17 figures, 6 table
The Fourth Standard Model Family and the Competition in Standart Model Higgs Boson Search at Tevatron and LHC
The impact of the fourth Standard Model family on Higgs boson search at
Tevatron and LHC is reviewed.Comment: 7 pages, 13 figure
Fourth Generation Pseudoscalar Quarkonium Production and Observability at Hadron Colliders
The pseudoscalar quarkonium state, eta_4 1^S_0, formed by the Standard Model
(SM) fourth generation quarks, is the best candidate among the fourth
generation quarkonia to be produced at the LHC and VLHC. The production of this
J^{PC} = 0^{-+} resonance is discussed and the background processes are studied
to obtain the integrated luminosity limits for the discovery, depending on its
mass.Comment: 13 pages, 4 figures, 5 table
Probing Little Higgs Model in e+ e- --> nu nubar gamma Process
We study the process e+e- -->nu nubar gamma to search for its sensitivity to
the extra gauge bosons Z_2, Z_3 and W_2 which are suggested by the little Higgs
models. We find that the ILC with sqrt(s)=0.5 TeV and CLIC with sqrt(s)=3 TeV
cover different regions of the LHM parameters. We show that this channel can
provide accurate determination of the parameters, complementary to measurements
of the extra gauge bosons at the coming LHC experiments.Comment: 17 pages, 10 figures, 5 table
Unparticle Searches Through Gamma Gamma Scattering
We investigate the effects of unparticles on gamma gamma--> gamma gamma
scattering for photon collider mode of the future multi-TeV e^+e^- linear
collider. We show the effects of unparticles on the differential, and total
scattering cross sections for different polarization configurations.
Considering 1-loop Standard Model background contributions from the charged
fermions, and W^{+-} bosons to the cross section, we calculate the upper limits
on the unparticle couplings lambda_0 to the photons for various values of the
scaling dimension d(1<d<2) at sqrt{s}=0.5-5 TeV.Comment: 15 pages, 5 figures, 2 table
Consequences of the extra SM families on the Higgs boson production at Tevatron and LHC
The latest electroweak precission data allow the existence of additional
chiral generations in the standard model. We study the influence of extra
generations on the production of SM Higgs boson at hadron colliders. Due to the
enhancement of the gluon fusion channel, the ``golden mode'' becomes more
promising even at upgraded Tevatron. Furthermore, the formation of the fourth
family quarkonia with the subsequent decay introduces
additional tool for the investigation of the Higgs boson properties.Comment: 12 pages, 6 figures, 2 table
Localization and Amount of Thyroid Remnant in Totally Thyroidectomized
Objective:To determine the frequency, localization and amount of thyroid remnant in extracapsular thyroidectomized patients.Methods:We postoperatively evaluated the thyroid bed of 38 totally thyroidectomized patients using thyroid scintigraphy, a thyroid uptake study and bilateral neck ultrasonography (US) to determine the extent of residual thyroid tissues.Results:In scintigraphic assessment, thyroid remnant was not seen in the thyroid bed in 13 cases, minimal thyroid remnant was detected in 15 cases, and visible uptake was seen in 10 cases. Ultrasonographic findings revealed the presence of remnant in 12 cases. However, US did not detect all remnant tissues diagnosed by TS.Conclusion:This study demonstrates that minimal thyroid remnant is left in the majority of cases, even after extracapsular total thyroidectomy, especially in the upper and middle zones
Turner syndrome and associated problems in turkish children: A multicenter study
Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology
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