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Analysis of b→cτν¯_(τ)anomalies using weak effective Hamiltonian with complex couplings and their impact on various physical observables

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Chinese Physics C 2024年第8期48卷 56-75页

作者： Muhammad Arslan Tahira Yasmeen Saba Shafaq ishtiaq ahmed Muhammad Jamil Aslam Department of Physics Quaid-i-Azam UniversityIslamabad 45320Pakistan Department of Physics International Islamic UniversityIslamabad 44000Pakistan National Center for Physics Islamabad 44000Pakistan

Recently,the experimental measurements of the branching ratios and different polarization asymmetries for processes occurring through flavor-changing-charged current(b→cτν¯_(τ))transitions by BABAR,Belle,and LHCb have revealed some significant differences from the corresponding Standard Model(SM)*** has triggered an interest to search for physics beyond the SM in the context of various new physics(NP)models and using the model-independent weak effective Hamiltonian(WEH).Assuming left-handed neutrinos,we add the dimension-six vector,(pseudo-)scalar,and tensor operators with complex Wilson coefficients(WCs)to the SM *** 60%,30%,and 10%constraints resulting from the branching ratio of B_(c)→τν¯_(τ),we reassess the parametric space of these new physics WCs accommodating the current anomalies based on the most recent HFLAV data of R_(τ/μ,e)(D)and R_(τ/μ,e)(D^(*))and Belle data of F_(L)(D^(*))and P_(τ)(D^(*)).We find that the allowed parametric region of left-handed scalar couplings strongly depends on the constraints of the B_(c)→τν¯_(τ)branching ratio,and the maximum pull from the SM predictions results from the<60%branching ratio ***,the parametric region changes significantly if we extend the analysis by adding LHCb data of R_(τ/μ)(J/ψ)and R_(τ/ℓ)(Λ_(c)).Furthermore,due to the large uncertainties in the measurements of R_(τ/μ)(J/ψ)and R_(τ/ℓ)(X_(c)),we derive the sum rules which complement them with R_(τ/μ,e)(D)and R_(τ/μ,e)(D^(*)).Using the best-fit points of the new complex WCs along with the latest measurements of R_(τ/μ,e)(D(^(*))),we predict the numerical values of the observable R_(τ/ℓ)(Λ_(c)),R_(τ/μ)(J/ψ),and R_(τ/ℓ)(X_(c))from the sum *** simultaneous dependence of abovementioned physical observables on the NP WCs is established by plotting their correlation with R_(D) and R_(D^(*)),which are useful to discriminate between various NP *** find that the most significant impact of NP results from the WC C^(S)_(L)=4C^(T).Fi

关键词： B meson anomalies new physics complex coupling HFLAV

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Analysis of b→cτ■ anomalies using weak effective Hamiltonian with complex couplings and their impact on various physical observables

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Chinese Physics C 2024年第8期 59-78页

作者： Muhammad Arslan Tahira Yasmeen Saba Shafaq ishtiaq ahmed Muhammad Jamil Aslam Department of Physics Quaid-i-Azam University Department of Physics International Islamic University National Center for Physics

Recently,the experimental measurements of the branching ratios and different polarization asymmetries for processes occurring through flavor-changing-charged current（b→cτvτ）transitions by BABAR,Belle,and LHCb have revealed some significant differences from the corresponding Standard Model（SM） *** has triggered an interest to search for physics beyond the SM in the context of various new physics（NP） models and using the model-independent weak effective Hamiltonian（WEH）.Assuming left-handed neutrinos,we add the dimension-six vector,（pseudo-）scalar,and tensor operators with complex Wilson coefficients（WCs） to the SM *** 60%,3 0%,and 10% constraints resulting from the branching ratio of Bc→τvτ,we reassess the parametric space of these new physics WCs accommodating the current anomalies based on the most recent HFLAV data of Rτ/μ,e（D） and Rτ/μ,e（D*） and Belle data of FL（D*） and Pτ（D*）.We find that the allowed parametric region of lefthanded scalar couplings strongly depends on the constraints of the Bc→τvτbranching ratio,and the maximum pull from the SM predictions results from the <60% branching ratio ***,the parametric region changes significantly if we extend the analysis by adding LHCb data of Rτ/μ（J/ψ） and Rτ/l（Λc）.Furthermore,due to the large uncertainties in the measurements of Rτ/μ（J/ψ） and Rτ/l（Xc）,we derive the sum rules which complement them with Rτ/μ,e（D） and Rτ/μ,e（D*）.Using the best-fit points of the new complex WCs along with the latest measurements of Rτ/μ,e(D（*）),we predict the numerical values of the observable Rτ/l（Λc）,Rτ/μ（J/ψ）,and Rτ/l（Xc） from the sum *** simultaneous dependence of abovementioned physical observables on the NP WCs is established by plotting their correlation with RDand RD*,which are useful to discriminate between various NP *** find that the most significant impact of NP results from the WC CLS=***,we study the impact of these NP couplings on various angular and CP triple product asym

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LHCb anomaly in B→K~*μ^+μ^- optimised observables and potential of Z' model

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Chinese Physics C 2018年第6期42卷 23-36页

作者： ishtiaq ahmed Abdur Rehman National Centre for Physics Quaid-i-Azam University Campus

Over the last few years LHCb found some discrepancies in b → sl^＋l^-FCNC transitions, including anomalies in the angular observables of B→K^＊μ^＋μ^-, particularly in P′5, in the low dimuon mass region. Recently,these anomalies have been confirmed by Belle, CMS and ATLAS. As direct evidence of physics beyond the Standard Model is absent so far, these anomalies are being interpreted as indirect hints of new physics. In this context, we study the implications of the family non-universal Z′ model for the angular observables P（1,2,3）, P′（4,5,6） and newly proposed lepton flavor universality violation observables, Q（4,5）, in the B → K^＊（→Kπ）μ^＋μ^-decay channel in the low dimuon mass region. To see the variation in the values of these observables from their Standard Model values, we have chosen different scenarios for the Z′ model. It is found that these angular observables are sensitive to the values of the parameters of the Z′ model. We have also found that with the present parametric space of the Z′ model,the P′5-anomaly could be accommodated. However, more statistics on the anomalies in the angular observables are helpful to reveal the status of the considered model and, in general, the nature of new physics.

关键词： FCNC new physics semileptonic B meson decays

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Modeling Components and Services of LTE Mobile Communications System

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International Journal of Communications, Network and System Sciences 2012年第12期5卷 815-824页

作者： ishtiaq ahmed Choudhry Nazir Ahmad Zafar Department of Communication and Networking King Faisal University Al-Ahsa KSA Department of Computer Science King Faisal University Al-Ahsa KSA

The latest wireless broadband network standard is LTE (Long Term Evolution) which is developed by 3GPP (3rd Generation Partnership Project). It will enable mobile devices such as smart phones, tablets and laptops to access Internet at a very high speed along with lots of multimedia services. There are many issues that are yet to be solved due to dynamic complex nature of wireless systems, multimedia software applications and software requirements. Poor service quality, service disconnections due to mobility, seamless handover, handover interruption time and downward compatibility to other Radio Access Networks (RAN) are some of the key issues for the current LTE systems that are addressed very recently in the scientific literature. Formal method is one of the promising software engineering techniques that assure quality and perfection in software system models. Formal methods use mathematical language to explicitly specify system specifications and requirements that serve as initial grounds for further development and implementation. It efficiently handles all component connections and resource management parameters using discrete structures. Z Schema language is used to model static aspects of LTE communications system. All the schemas are being verified using Z/Eves toolset. The aim is to provide sound mathematical foundation for system validation and verification that eventually results in a more reliable, scalable and complete software system.

关键词： LTE Communications System Formal Methods Emerging Software Mathematical Language Z Notation

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Structural Interpretation and Petrophysical Analysis for Reservoir Sand of Lower Goru, Miano Area, Central Indus Basin, Pakistan

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International Journal of Geosciences 2017年第4期8卷 379-392页

作者： Muhammad Sohail Khan Farhana Masood Qadeer ahmed ishtiaq ahmed Khan Jadoon Naveed Akram School of Earth and Space Sciences University of Science and Technology of China Hefei China Quaid-i-Azam University Islamabad Pakistan Oil and Gas Development Company Limited Islamabad Pakistan COMSATS Institute of Information Technology Abbottabad Pakistan

The main purpose of this research is to estimate the structural analysis and hydrocarbon potential of Miano Block by using seismic and well log techniques. Miano area hosts a number of gas fields with structural and stratigraphic traps. The area is located in Central Indus Basin which is a part of an extensional regime exhibiting normal faulting due to the split of the Indian Plate firstly from Africa and then from Madagascar and Seychelles. Miano area recognized as a proven petroleum province which has complex tectonic history of Cretaceous extensional and overprints of Tertiary strike-slip tectonics. The area has prospect with accumulation of hydrocarbons in structural and stratigraphic traps including pinchouts. NW-SE oriented Khairpur and Mari Highs are main structural features with impact on the fault system. The sands of Lower Goru of Lower Cretaceous age are acting as a reservoir in the area. The area has great potential of hydrocarbons for which more exploratory wells are required to be drilled with better insight of structural and stratigraphic traps.

关键词： Seismic Interpretation Time-and-Depth Contour Map 3D View Synthetic Seismograph Reservoir Estimation

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Enhanced bio-catalytic and tolerance properties of an indigenous cellulase through xerogel immobilization

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Advances in Bioscience and Biotechnology 2012年第4期3卷 308-313页

作者： Hafiz Muhammad Nasir Iqbal Shagufta Kamal ishtiaq ahmed Muhammad Tahir Naveed Department of Chemistry and Biochemistry University of Agriculture Faisalabad Pakistan Transgenic Lab Center of Agriculture Biochemistry and Biotechnology (CABB) University of Agriculture Faisalabad Pakistan

Today, demand exists for cost-effective production of industrially important enzymes from entire scientific sectors. By keeping in mind the extensive industrial applications of cellulase, this study was performed to immobilize the indigenous enzyme produced from Trichoderma viride under pre-optimized SSF of an agricultural waste material, wheat straw. To enhance the bio-catalytic and tolerance properties of the present enzyme gel matrix immobilization engineering was applied. Previously, 2.33~fold purified novel cellulase was immobilized in to a xerogel matrix of TMOS and PTMS. FTIR spectroscopy confirmed the successful immobilization of cellulase. The free and immobilized cellulase was characterized and stability profile showed that after 24 h incubation, immobilization enhanced the thermo-stability up to 75% against 80℃ as compare to the free enzyme. Xerogel matrix immobilization enhanced the catalytic efficiency of entrapped enzyme than that of the free cellulase. Among activators/inhibitors SDS, EDTA, and Hg2+ showed inhibitory effect while, gel matrix immobilization enhanced 80% tolerance capacity of the cellulase against inactivating agents.

关键词： Bio-Catalysis Cellulase T. viride Immobilization Characterization

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Purification and characterization of the kinetic parameters of cellulase produced from wheat straw by Trichoderma viride under SSF and its detergent compatibility

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Advances in Bioscience and Biotechnology 2011年第3期2卷 149-156页

作者： Hafiz Muhammad Nasir Iqbal ishtiaq ahmed Muhammad Anjum Zia Muhammad Irfan 不详

This paper reports the purification and characterization of kinetic parameters of cellulase produced from Trichoderma viride under still culture solid state fermentation technique using cheap and an easily available agricultural waste material, wheat straw as growth supported substrate. Trichoderma viride was cultured in fermentation medium of wheat straw under some previously optimized growth conditions and maximum activity of 398±2.43U/mL obtained after stipulated fermentation time period. Cellulase was purified 2.33 fold with specific activity of 105U/mg in comparison to crude enzyme extract using ammonium sulfate precipitation, dialysis and Sephadex-G-100 column chromatography. The enzyme was shown to have a relative low molecular weight of 58kDa by sodium dodecyl sulphate poly-acrylamide gel electrophoresis. The purified enzyme displayed 6.5 and 55oC as an optimum pH and temperature respectively. Using carboxymethyl cellulose as substrate, the enzyme showed maximum activity (Vmax) of 148U/mL with its corresponding KM value of 68μM. Among activators/inhibitors SDS, EDTA, and Hg2+ showed inhibitory effect on purified cellulase whereas, the enzyme activated by Co2+ and Mn2+ at a concentration of 1mM. The purified cellulase was compatible with four local detergent brands with up to 20 days of shelf life at room temperature suggesting its potential as a detergent additive for improved washing therefore, it is concluded that it may be potentially useful for industrial purposes especially for detergent and laundry industry.

关键词： Cellulase Trichoderma viride Purification SDS-PAGE Characterization Detergent Compatibility

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水生生物学报 2011年第5期35卷 727-738页

作者： Abu Shufian ishtiaq ahmed 于力群朱作言孙永华中国科学院水生生物研究所淡水生态与生物技术国家重点实验室武汉430072

GHR信号通路在动物出生后的生长中扮演着重要角色。实验利用斑马鱼模型研究了GHR信号相关基因在成体组织、胚胎发育以及幼体期的表达情况,这些基因包括gh、ghra、ghrb、jak2a、jak2b、stat5.1、stat5.2、igf1、c-fos、socs1和socs2。值... 详细信息

GHR信号通路在动物出生后的生长中扮演着重要角色。实验利用斑马鱼模型研究了GHR信号相关基因在成体组织、胚胎发育以及幼体期的表达情况,这些基因包括gh、ghra、ghrb、jak2a、jak2b、stat5.1、stat5.2、igf1、c-fos、socs1和socs2。值得关注的是,上述的大部分基因都存在母源性表达,且它们的合子表达均起始在体节早期之前。这说明在有功能性的脑垂体形成之前和完善的循环系统建立之前,GH及GH信号相关因子就已经存在于早期胚胎中,因此GH很可能是控制胚胎发育的一系列自分泌/旁分泌生长因子中的一员。同时,我们发现成体组织的socs表达水平与GH信号靶基因igf1和c-fos的表达呈某种程度的负相关。我们利用实时定量PCR技术和荧光素酶分析技术,通过注射GH和GHR表达载体,在斑马鱼胚胎中分析了它们促进GH信号靶基因c-fos和igf1转录活性以及GH应激启动子spi2.1活性的能力。由此,研究利用斑马鱼胚胎建立一个体内研究模型来评估发育过程中的GH信号激活(GHSA)。在受精后1天(dpf)和3dpf斑马鱼胚胎中,单独过表达gh或ghr均可以显著刺激GHSA,这表明在1dpf的斑马鱼胚胎中即存在功能性的GH和GHR蛋白表达,而这一时期是在功能性垂体的形成之前的。gh以及ghr的协同过表达则可以显著放大gh或ghr单独过表达的GHSA效果。

关键词：生长激素生长激素受体 GHR信号通路斑马鱼转录分析

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Effect of aging on stem cells

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World Journal of Experimental Medicine 2017年第1期7卷 1-10页

作者： Abu Shufian ishtiaq ahmed Matilda HC Sheng Samiksha Wasnik David J Baylink Kin-Hing William Lau Regenerative Medicine Unit Department of MedicineLoma Linda University School of Medicine Musculoskeletal Disease Center Jerry L.Pettis Memorial VA Medical Center

Pluripotent stem cells have the remarkable self-renewal ability and are capable of differentiating into multiple diverse cells. There is increasing evidence that the aging process can have adverse effects on stem cells. As stem cells age, their renewal ability deteriorates and their ability to differentiate into the various cell types is altered. Accordingly, it is suggested aging-induced deterioration of stem cell functions may play a key role in the pathophysiology of the various aging-associated disorders. Understanding the role of the aging process in deterioration of stem cell function is crucial, not only in understanding the pathophysiology of agingassociated disorders, but also in future development of novel effective stem cell-based therapies to treat agingassociated diseases. This review article first focuses on the basis of the various aging disease-related stem cell dysfunction. It then addresses the several concepts on the potential mechanism that causes aging-related stem cell dysfunction. It also briefly discusses the current potential therapies under development for aging-associated stem cell defects.

关键词： Aging Biological aging Cellular aging Adult stem cells Premature aging Mesenchymal stem cell Stem cell renewal Tissue regeneration

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The Space-Time CE/SE Method for Solving Reduced Two-Fluid Flow Model

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Communications in Computational Physics 2012年第9期12卷 1070-1095页

作者： Shamsul Qamar Munshoor ahmed ishtiaq Ali Department of Mathematics COMSATS Institute of Information TechnologyPark RoadChak Shahzad IslamabadPakistan Max Planck Institute for Dynamics of Complex Technical Systems Sandtorstr.139106 MagdeburgGermany

The space-time conservation element and solution element(CE/SE)method is proposed for solving a conservative interface-capturing reducedmodel of compressible two-fluid *** flow equations are the bulk equations,combined with mass and energy equations for one of the two *** latter equation contains a source term for accounting the energy *** one and two-dimensional flow models are numerically investigated in this *** CE/SE method is capable to accurately capture the sharp propagating wavefronts of the fluids without excessive numerical diffusion or spurious *** contrast to the existing upwind finite volume schemes,the Riemann solver and reconstruction procedure are not the building block of the suggested *** method differs from the previous techniques because of global and local flux conservation in a space-time domain without resorting to interpolation or *** order to reveal the efficiency and performance of the approach,several numerical test cases are *** validation,the results of the current method are compared with other finite volume schemes.

关键词： Reduced model space-time CE/SE method central schemes conservation laws hyperbolic systems shock solutions

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