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Related papers: Quartic Mass Corrections to $R_{had}$

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We compute the leading-order collisional energy loss of a heavy quark propagating through a quark-gluon plasma in which the quark and gluon distributions are anisotropic in momentum space. Following the calculation outlined for QED in an…

High Energy Physics - Phenomenology · Physics 2009-11-10 Paul Romatschke , Michael Strickland

To reduce errors in light-quark mass determinations, it is now necessary to consider electromagnetic contributions to light-meson masses. Calculations using staggered quarks and quenched photons are currently underway. Suitably-extended…

High Energy Physics - Lattice · Physics 2010-11-18 C. Bernard , E. D. Freeland

Moller Scattering and Bhabha Scattering on noncommutative space-time is restudied. It is shown that the noncommutative correction of scattering cross sections is not monotonous enhancement with the total energy of colliding electrons, there…

High Energy Physics - Theory · Physics 2009-11-10 Zheng-Mao Sheng , Yongming Fu , Haibo Yu

The summary of the available semi-analytical results for the three-loop corrections to the QCD static potential and for the $\mathcal{O}(\alpha_s^4)$ contributions to the ratio of the running and pole heavy quark masses are presented. The…

High Energy Physics - Phenomenology · Physics 2016-12-21 A. L. Kataev , V. S. Molokoedov

We extend the epsilon-expansion of continuum chiral perturbation theory to nonzero lattice spacing in the framework of Wilson Chiral Perturbation Theory. We distinguish various regimes by defining the relative power counting of the quark…

High Energy Physics - Lattice · Physics 2010-11-05 Oliver Bar , Silvia Necco , Stefan Schaefer

We develop quenched chiral perturbation theory for vector mesons made of light quarks, in the limit where the vector meson masses are much larger than the pion mass. We use this theory to extract the leading nonanalytic dependence of the…

High Energy Physics - Phenomenology · Physics 2009-10-30 Michael Booth , George Chiladze , Adam F. Falk

Considered as a function of the quark mases, two-flavor QCD depends on three parameters, including one that is CP violating. As the masses vary to unphysical values, regions of both first- and second-order phase transitions are expected.…

High Energy Physics - Phenomenology · Physics 2011-10-20 Michael Creutz

The decay of B mesons can be predicted within the Heavy Quark Expansion as the decay of a free bottom quark plus corrections which are suppressed by powers of $1/m_b$. This contribution to Loops&Legs 2024 describes the calculation of the…

High Energy Physics - Phenomenology · Physics 2024-07-02 Manuel Egner

The matrix element of a bound electron interacting with the nucleus through exchange of a Z boson is studied for the gauge invariant case of $2s_{1/2}-2p_{1/2}$ transitions in hydrogenic ions. The QED radiative correction to the matrix…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. Sapirstein , K. Pachucki , A. Veitia , K. T. Cheng

QCD corrections to $e^+e^- \ra WW \ra q_1 \bar q_1 q_2 \bar q_2$ are computed and presented in a form which allows to impose realistic cuts on the structure of the observed events. QCD radiation substantially modifies the jet--jet invariant…

High Energy Physics - Phenomenology · Physics 2009-10-28 E. Maina , M. Pizzio

I discuss radiative corrections due to the emission of photons from quarks which contribute to deep inelastic lepton--nucleon scattering as well as to $pp$ collisions at high energies. These corrections are dominated by quark-mass…

High Energy Physics - Phenomenology · Physics 2014-11-17 H. Spiesberger

A method for computing electromagnetic properties of hadrons in lattice QCD is described. The electromagnetic field is introduced dynamically, using a noncompact formulation. Employing enhanced electric charges, the dependence of the…

High Energy Physics - Lattice · Physics 2009-10-28 A. Duncan , E. Eichten , H. Thacker

We calculate electromagnetic mass difference of mesons using a method proposed by Duncan {\it et al}. The RG-improved gauge action and the non-compact Abelian gauge action are employed to generate configurations. Quark propagators in the…

High Energy Physics - Lattice · Physics 2007-05-23 Yusuke Namekawa , Yoshio Kikukawa

We examine the leading order noncommutative corrections to the differential and total cross sections for e+ e- --> q q-bar. After averaging over the earth's rotation, the results depend on the latitude for the collider, as well as the…

High Energy Physics - Phenomenology · Physics 2014-11-21 Mansour Haghighat , Nobuchika Okada , Allen Stern

Heavy quark effective theory can be used to calculate the values of the semileptonic B^(*) -> D^(*) decays in the limit that the heavy quark masses are infinite. We calculate the lowest order chiral corrections, which are of O(1/M^2), from…

High Energy Physics - Lattice · Physics 2009-11-07 Daniel Arndt

In the event that the Higgs mass is large or that the electroweak interactions are strongly interacting at high energy, top quark couplings to longitudinal components of the weak gauge bosons could offer important clues to the underlying…

High Energy Physics - Phenomenology · Physics 2016-09-06 Stephen Godfrey , Shou-hua Zhu

Meson-meson nonresonant reactions governed by the quark-interchange mechanism are studied in a potential that is derived from QCD. S-wave elastic phase shifts for I=2 \pi\pi and I=3/2 K \pi scattering are obtained with wave functions…

Nuclear Theory · Physics 2008-11-26 Yu-Qi Li , Xiao-Ming Xu

Using the Cottingham formula, we give an estimate of the electromagnetic mass splitting of pseudoscalar heavy mesons in the beauty and charm sector. We include in the dispersion relation the Born term, the $1^-$ resonance and the positive…

High Energy Physics - Phenomenology · Physics 2011-01-27 P. Colangelo , M. Ladisa , G. Nardulli , T. N. Pham

The leading electroweak MSSM two-loop corrections to the $\rho$-parameter are calculated. They are obtained by evaluating the two-loop self-energies of the Z and the W boson at O(Gf^2 m_t^4) in the limit of heavy scalar quarks. A very…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Heinemeyer , G. Weiglein

We study the finite quark mass effects of the low-energy QCD using the improved ladder Schwinger-Dyson and Bethe-Salpeter equations which are derived in the manner consistent with the vector and axial-vector Ward-Takahashi identities. The…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. Naito , K. Yoshida , Y. Nemoto , M. Oka , M. Takizawa