scholarly journals PHENOMENOLOGY FROM LATTICE QCD

2002 ◽  
Vol 17 (23) ◽  
pp. 3140-3153 ◽  
Author(s):  
C. T. SACHRAJDA
Keyword(s):  
Particle Physics ◽  
Significant Contribution ◽  
Form Factors ◽  
Decay Rates ◽  
Experimental Measurements ◽  
B Decays ◽  
Unitarity Triangle ◽  
Decay Constants ◽  
The Status

I review two subject in which lattice simulations are making, or can make in the future, a significant contribution to particle physics phenomenology. The first subject is the evaluation of quantities which enter into the determination of the vertex A of the unitarity triangle from experimental measurements of decay rates and mixing amplitudes. These quantities include the form-factors for semileptonic B-decays, the leptonic decay constants of the B and Bs mesons and the B-parameters for [Formula: see text] and [Formula: see text] mixing and the corresponding parameter for [Formula: see text] mixing, BK. In the second part of this talk I will review the status and prospects for the evaluation of K → π π amplitudes and for the subsequent study of the Δ I = 1/2 rule and the evalution of ε′/ε.

scholarly journals FLAG Review 2019

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
S. Aoki ◽  
Y. Aoki ◽  
D. Bečirević ◽  
T. Blum ◽  
G. Colangelo ◽  
...  
Keyword(s):  
Heavy Quark ◽  
Particle Physics ◽  
Light Quark ◽  
Form Factors ◽  
Matrix Elements ◽  
Ckm Matrix ◽  
Quark Masses ◽  
The Status ◽  
Ckm Matrix Elements

Abstract We review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor $$f_+(0)$$f+(0) arising in the semileptonic $$K \rightarrow \pi $$K→π transition at zero momentum transfer, as well as the decay constant ratio $$f_K/f_\pi $$fK/fπ and its consequences for the CKM matrix elements $$V_{us}$$Vus and $$V_{ud}$$Vud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of $$SU(2)_L\times SU(2)_R$$SU(2)L×SU(2)R and $$SU(3)_L\times SU(3)_R$$SU(3)L×SU(3)R Chiral Perturbation Theory. We review the determination of the $$B_K$$BK parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for $$m_c$$mc and $$m_b$$mb as well as those for D- and B-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant $$\alpha _s$$αs. Finally, in this review we have added a new section reviewing results for nucleon matrix elements of the axial, scalar and tensor bilinears, both isovector and flavor diagonal.

scholarly journals B → D*lv at non-zero recoil

2018 ◽  
Vol 175 ◽  
pp. 13003 ◽  
Author(s):  
Alejandro Vaquero Avilés-Casco ◽  
Carleton DeTar ◽  
Daping Du ◽  
Aida El-Khadra ◽  
Andreas Kronfeld ◽  
...  
Keyword(s):  
Matrix Element ◽  
Decay Rate ◽  
Form Factors ◽  
Heavy Quarks ◽  
Experimental Measurements ◽  
Ckm Matrix ◽  
Preliminary Results ◽  
Future Plans

We present preliminary results from our analysis of the form factors for the B → D*lv decay at non-zero recoil. Our analysis includes 15 MILC asqtad ensembles with Nf = 2 + 1 flavors of sea quarks and lattice spacings ranging from a ≈ 0.15 fm down to 0.045 fm. The valence light quarks employ the asqtad action, whereas the heavy quarks are treated using the Fermilab action. We conclude with a discussion of future plans and phenomenological implications. When combined with experimental measurements of the decay rate, our calculation will enable a determination of the CKM matrix element |Vcb|.

scholarly journals QUARK MIXING AND CP VIOLATION — THE CKM MATRIX

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1724-1737 ◽  
Author(s):  
ULRICH NIERSTE
Keyword(s):  
Neutral Current ◽  
New Physics ◽  
Tree Level ◽  
B Decays ◽  
Ckm Matrix ◽  
Penguin Decays ◽  
The Status ◽  
First Results ◽  
Global Fit

I summarize the theoretical progress in the determination of the CKM elements since Lepton-Photon 2003 and present the status of the elements and parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. One finds |Vus| = 0.2227 ± 0.0017 from K and τ decays and |Vcb| = (41.6 ± 0.5) · 10-3 from inclusive semileptonic B decays. The unitarity triangle can now be determined from tree-level quantities alone and the result agrees well with the global fit including flavour-changing neutral current (FCNC) processes, which are sensitive to new physics. From the global fit one finds the three CKM angles θ12 = 12.9° ± 0.1°, θ23 = 2.38° ± 0.03° and θ13 = 0.223° ± 0.007° in the standard PDG convention. The CP phase equals [Formula: see text] at 1σ CL and [Formula: see text] at 2σ CL. A major progress are first results from fully unquenched lattice QCD computations for the hadronic quantities entering the UT fit. I further present the calculation of three-loop QCD corrections to the charm contribution in [Formula: see text] decays, which removes the last relevant theoretical uncertainty from the [Formula: see text] system. Finally I discuss mixing-induced CP asymmetries in [Formula: see text] penguin decays, whose naive average is below its Standard Model value by 3σ.

scholarly journals B DECAYS ON THE LATTICE AND RESULTS FOR PHENOMENOLOGY

2005 ◽  
Vol 20 (16) ◽  
pp. 3651-3653
Author(s):  
MATTHEW WINGATE ◽  
CHRISTINE DAVIES ◽  
ALAN GRAY ◽  
EMEL GULEZ ◽  
JUNKO SHIGEMITSU ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Form Factors ◽  
Matrix Elements ◽  
B Decays ◽  
Ckm Matrix ◽  
Decay Constants ◽  
Lattice Monte Carlo ◽  
Ckm Matrix Elements ◽  
Fermion Action

Lattice Monte Carlo simulations now include the effects of 2 light sea quarks and 1 strange sea quark through the use of an improved staggered fermion action. Consequently, results important to phenomenology are free of the approximate 10% errors inherent in the quenched approximation. This talk reports on calculations of the B and Bs, decay constants and B → πℓν form factors. Accurate determinations of these quantities will lead to tighter constraints on CKM matrix elements.

scholarly journals CKM PARAMETERS AND RARE B DECAYS

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1683-1696 ◽  
Author(s):  
FRANCESCO FORTI
Keyword(s):  
B Meson ◽  
New Physics ◽  
Precise Determination ◽  
Model Parameters ◽  
B Decays ◽  
Unitarity Triangle ◽  
Indirect Determination ◽  
Radiative Transitions ◽  
First Time

Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the loop diagrams. In this paper the recent measurements performed in this area by BABAR and Belle will be presented. The direct measurement of the angle α is for the first time as precise as the indirect determination. The precision of the |Vub| determination has improved significantly with respect to previous measurement. New limits on B → τν decays are presented, as well as updated measurements on b → s radiative transitions and a new observation of b → dγ transition made by Belle.

scholarly journals B DECAYS AND CP VIOLATION

1996 ◽  
Vol 11 (23) ◽  
pp. 4173-4239 ◽  
Author(s):  
MATTHIAS NEUBERT
Keyword(s):  
Cp Violation ◽  
B Mesons ◽  
B Meson ◽  
Decay Rates ◽  
B Decays ◽  
Weak Decays ◽  
B Hadrons ◽  
Heavy Quark Symmetry ◽  
The Status ◽  
Inclusive Decay

We review the status of the theory and phenomenology of heavy-quark symmetry, exclusive weak decays of B mesons, inclusive decay rates and lifetimes of b hadrons, and CP violation in B-meson decays.

scholarly journals B → πlv with Möbius Domain Wall Fermions

2018 ◽  
Vol 175 ◽  
pp. 13004 ◽  
Author(s):  
Brian Colquhoun ◽  
Shoji Hashimoto ◽  
Takashi Kaneko
Keyword(s):  
Domain Wall ◽  
Lattice Spacing ◽  
Semileptonic Decay ◽  
Form Factors ◽  
Heavy Quarks ◽  
Ckm Matrix ◽  
Domain Wall Fermions ◽  
Heavy Quark Mass ◽  
The Status

We report on the status of our calculation of the exclusive semileptonic decay, B → πlv; a key process in the determination of the CKM matrix element |Vub|. The Möbius domain wall action is used for both light and heavy quarks on gauge ensembles that include the effects of 2 + 1 flavours of quarks in the sea at three values of the lattice spacing: a ≈ 0.08 fm, a ≈ 0.055 fm, and a ≈ 0.044 fm. Pion masses go down to 300 MeV while heavy quarks masses are as large as 2.44mc. We present preliminary results of form factors from this process, showing dependence on momentum transfer, lattice spacing, and the heavy quark mass.

The Validity of Rector�s Circular Letter on the Covid-19 Pandemic

2020 ◽  
Vol 7 (1) ◽  
pp. 126 ◽  
Author(s):  
Fradhana Putra Disantara
Keyword(s):  
Legal Theory ◽  
Legal Issues ◽  
State Universities ◽  
Ministry Of Education ◽  
Conceptual Approach ◽  
State Of Emergency ◽  
Circular Letter ◽  
The Status ◽  
The Government

This study aims to analyze the relevance of the �health emergency� status to the existing legal theory and condition as well as to identify the validity of the Circular Letter of the Rector of State Universities. To this end, this study applied the statute and conceptual approach. The study was conducted by inventorying primary and secondary legal materials to obtain a proper and critical review of the legal issues under study. The results showed that the determination of the �health emergency� status by the government was inappropriate due to the uncertainty of the regulations issued by the government to determine the current condition. Thus, the status of the COVID-19 pandemic is a �legal emergency� status. Further, the Rector�s policy through the Circular Letter is valid judicially, sociologically, and philosophically. The determination of the �legal emergency� status can be done by issuing a Perppu without a �state of emergency� from the President. Finally, it is suggested to firstly get an approval from the Ministry of Education and Culture regarding the issuance of the Rector�s Circular Letter. Besides, further study is needed as this study was conducted during the COVID-19 pandemic.�Keabsahan Surat Edaran Rektor Perguruan Tinggi dalam Pandemi Covid-19Tujuan dari penelitian ini adalah untuk menganalisa relevansi status �darurat kesehatan� dengan teori hukum dan kondisi yang ada dan keabsahan atas Surat Edaran Rektor Perguruan Tinggi Negeri. Metode yang digunakan dalam penelitian ini adalah statute approach dan conseptual approach. Penelitian dilakukan dengan menginventarisasi bahan hukum primer dan sekunder, guna mendapatkan kajian yang seyogianya dan telaah kritis terkait isu hukum. Hasil penelitian menyatakan penetapan status darurat kesehatan oleh pemerintah kurang tepat, dikarenakan tidak menentu-nya peraturan yang dikeluarkan oleh pemerintah untuk menetapkan kondisi saat ini. Sehingga, status pandemi COVID-19 merupakan status darurat hukum. Kebijakan rektor melalui Surat Edaran adalah absah secara aspek yuridis, sosiologis, dan filosofis. Penetapan darurat hukum cukup dilakukan dengan menerbitkan Perppu tanpa pernyataan darurat dari Presiden. Saran peneliti adalah di perlukan persetujuan pada Kementerian Pendidikan dan Kebudayaan terkait terbitnya Surat Edaran Rektor, dan dibutuhkan penelitian lebih lanjut dikarenakan penelitian ini dilakukan pada masa COVID-19 yang bersifat temporal.�

DARK MATTER SEARCH

2002 ◽  
Vol 17 (24) ◽  
pp. 3421-3431 ◽  
Author(s):  
◽  
H. V. KLAPDOR-KLEINGROTHAUS
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Exciting Field ◽  
Dark Matter Search ◽  
The Status

Dark matter is at present one of the most exciting field of particle physics and cosmology. We review the status of undergound experiments looking for cold and hot dark matter.

scholarly journals Bs → Kℓv form factors with 2+1 flavors

2018 ◽  
Vol 175 ◽  
pp. 13008 ◽  
Author(s):  
Yuzhi Liu ◽  
Jon A. Bailey ◽  
A. Bazavov ◽  
C. Bernard ◽  
C. M. Bouchard ◽  
...  
Keyword(s):  
Quark Mass ◽  
Strange Quark ◽  
Lattice Spacing ◽  
Light Quark ◽  
Form Factors ◽  
Ckm Matrix ◽  
Strange Quark Mass ◽  
Light Quark Mass ◽  
B Quark

Using the MILC 2+1 flavor asqtad quark action ensembles, we are calculating the form factors f0 and f+ for the semileptonic Bs → Kℓv decay. A total of six ensembles with lattice spacing from ≈ 0.12 to 0.06 fm are being used. At the coarsest and finest lattice spacings, the light quark mass m’l is one-tenth the strange quark mass m’s. At the intermediate lattice spacing, the ratio m’l/m’s ranges from 0.05 to 0.2. The valence b quark is treated using the Sheikholeslami-Wohlert Wilson-clover action with the Fermilab interpretation. The other valence quarks use the asqtad action. When combined with (future) measurements from the LHCb and Belle II experiments, these calculations will provide an alternate determination of the CKM matrix element |Vub|.

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