PHYSICS ISSUES IN η′ DECAYS

2005 ◽  
Vol 20 (02n03) ◽  
pp. 532-535 ◽  
Author(s):  
MAGNUS WOLKE
Keyword(s):  
Radiative Decay ◽  
Light Quark ◽  
Mass Difference ◽  
Experimental Information ◽  
Hadronic Decays ◽  
Fundamental Physics ◽  
Leptonic Decays ◽  
Light Quark Mass ◽  
Isospin Symmetry Breaking ◽  
Shed Light

Studies of hadronic, radiative, and (semi–)leptonic decays of the η′ allow to shed light on a broad field of fundamental physics questions. Isospin symmetry breaking decays provide a well-suited tool to extract the light quark mass difference. Differential distributions in hadronic decays both test predictions obtained within ChPT approaches, and enclose information on the scalar meson sector. Precision measurements on radiative decay widths will constrain pseudoscalar mixing, the manifestation of QCD anomalies, and the structure of the η′. The latter is also subject of investigation in semileptonic decays probing the η′ transition form factor. The presently available experimental information is reviewed, and prospects for η′ decay physics with WASA at COSY are presented.

scholarly journals B PHYSICS ON THE LATTICE: PRESENT AND FUTURE

2006 ◽  
Vol 21 (15) ◽  
pp. 1167-1182 ◽  
Author(s):  
MATTHEW WINGATE
Keyword(s):  
Lattice Qcd ◽  
Light Quark ◽  
Mass Difference ◽  
Current Status ◽  
Recent Measurement ◽  
Experimental Measurements ◽  
Decay Channels ◽  
Flavor Changing ◽  
Lattice Calculations ◽  
Light Quark Mass

Recent experimental measurements and lattice QCD calculations are now reaching the precision (and accuracy) needed to over-constrain the CKM parameters [Formula: see text] and [Formula: see text]. In this brief review, we discuss the current status of lattice QCD calculations needed to connect the experimental measurements of B meson properties to quark flavor-changing parameters. Special attention is given to B→πℓν, which is becoming a competitive way to determine |Vub|, and to [Formula: see text] mixings, which now include reliable extrapolation to the physical light quark mass. The combination of the recent measurement of the Bs mass difference and current lattice calculations dramatically reduces the uncertainty in |Vtd|. We present an outlook for reducing dominant lattice QCD uncertainties entering CKM fits and remark on lattice calculations for other decay channels.

τ → δν decay induced by light quark mass difference

1982 ◽  
Vol 115 (3) ◽  
pp. 264-266 ◽  
Author(s):  
S. Tisserant ◽  
Tran N. Truong
Keyword(s):  
Quark Mass ◽  
Light Quark ◽  
Mass Difference ◽  
Light Quark Mass

scholarly journals Isospin-1/2 Dπ scattering and the lightest $$ {D}_0^{\ast } $$ resonance from lattice QCD

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Luke Gayer ◽  
Nicolas Lang ◽  
Sinéad M. Ryan ◽  
David Tims ◽  
Christopher E. Thomas ◽  
...  
Keyword(s):  
Scattering Amplitudes ◽  
Lattice Qcd ◽  
Quark Mass ◽  
Light Quark ◽  
Energy Levels ◽  
Experimental Result ◽  
Infinite Volume ◽  
Resonance Pole ◽  
Strongly Coupled ◽  
Light Quark Mass

Abstract Isospin-1/2 Dπ scattering amplitudes are computed using lattice QCD, working in a single volume of approximately (3.6 fm)3 and with a light quark mass corresponding to mπ ≈ 239 MeV. The spectrum of the elastic Dπ energy region is computed yielding 20 energy levels. Using the Lüscher finite-volume quantisation condition, these energies are translated into constraints on the infinite-volume scattering amplitudes and hence enable us to map out the energy dependence of elastic Dπ scattering. By analytically continuing a range of scattering amplitudes, a $$ {D}_0^{\ast } $$ D 0 ∗ resonance pole is consistently found strongly coupled to the S-wave Dπ channel, with a mass m ≈ 2200 MeV and a width Γ ≈ 400 MeV. Combined with earlier work investigating the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ , and $$ {D}_0^{\ast } $$ D 0 ∗ with heavier light quarks, similar couplings between each of these scalar states and their relevant meson-meson scattering channels are determined. The mass of the $$ {D}_0^{\ast } $$ D 0 ∗ is consistently found well below that of the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ , in contrast to the currently reported experimental result.

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|.

Light quark mass differences in quantum chromodynamics

1983 ◽  
Vol 212 (3) ◽  
pp. 365-390 ◽  
Author(s):  
S. Narison ◽  
N. Paver ◽  
E. de Rafael ◽  
D. Treleani
Keyword(s):  
Quantum Chromodynamics ◽  
Quark Mass ◽  
Light Quark ◽  
Light Quark Mass

scholarly journals MEASUREMENT OF THE η → π+π-π0 DECAY WITH WASA-at-COSY DETECTOR

2011 ◽  
Vol 26 (03n04) ◽  
pp. 622-624
Author(s):  
◽  
PATRIK ADLARSON ◽  
MARCIN ZIELIŃSKI
Keyword(s):  
Dalitz Plot ◽  
Quark Mass ◽  
Mass Difference ◽  
Current Status ◽  
Hadronic Decays ◽  
Density Population ◽  
Physics Programme ◽  
Made In

One of the objectives of the physics programme of the WASA-at-COSY facility is to study the isospin violating η hadronic decays into π+π-π0 systems driven by the term of QCD Lagrangian which depends on the d and u quark mass difference. These studies can be made in terms of the Dalitz plot parameters describing the density population which is proportional to the square of the amplitude |A(x, y)|2. This contribution describes the current status of the analysis of the η → π+π-π0 decay in the pd →3 Heη and as well in the pp → ppη reaction with WASA-at-COSY.

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