We use QCD sum rules, in the framework of the heavy quark effective theory, to calculate the universal form factor ${\ensuremath{\tau}}_{1/2}(y)$ parametrizing the semileptonic transitions $\stackrel{\ensuremath{\rightarrow}}{B}{D}_{0}l\overline{\ensuremath{\nu}},$ $\stackrel{\ensuremath{\rightarrow}}{B}{D}_{1}^{*}l\overline{\ensuremath{\nu}},$ where ${D}_{0}$ and ${D}_{1}^{*}$ are the members of the excited charmed doublet with ${J}^{P}{=(0}_{1/2}^{+}{,1}_{1/2}^{+}).$ We include two-loop corrections in the perturbative contribution to the sum rule, and present a complete next-to-leading order result. As a preliminary part of our analysis we also compute, up to order ${\ensuremath{\alpha}}_{s},$ the leptonic constant ${F}^{+}$ of the doublet ${D}_{0},$ ${D}_{1}^{*}.$ Finally, we discuss the phenomenological implications of this calculation.

Bar (unit)

Semileptonic decay

10.1103/physrevd.58.116005

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Citations (56)

Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

arXiv (Cornell University) (2023)

Alberto Accardi P. Achenbach D. Adhikari Andrei Afanasev C. S. Akondi

This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena.

Hadronization

Upgrade

10.48550/arxiv.2306.09360

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Citations (19)

Heavy Flavour production at RHIC

AIP conference proceedings (2010)

S. Kabana Leonardo Angelini Pietro Colangelo Fulvia De Fazio G. Bruno

We present a review of Heavy Flavour production in p+p, d+Au and A+A collisions at the Relativistic Heavy Ion Collider (RHIC). We focus on two important topics, jet quenching and quarkonia. Anomalous energy loss (jet quenching) of quarks passing through the dense and hot matter build in heavy ion collisions is one of the outstanding discoveries made at RHIC, allowing for an estimate of the initial density. Furthermore, color screening of hidden charm and beauty states is a key signature of the QCD phase transition, allowing an estimate of the initial temperature. We present results on the flavour dependence of jet quenching. Heavy flavour production in A+A as compared to p+p collisions will be discussed for open and hidden charm.

Jet quenching

Flavour

Charm (quantum number)

QCD matter

10.1063/1.3536567

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On the decay mode Λb → Xsγ

Journal of High Energy Physics (2023)

Pietro Colangelo Fulvia De Fazio Francesco Loparco

A bstract We study the inclusive H b → X s γ decay with H b a beauty baryon, in particular Λ b , employing an expansion in the heavy quark mass at $$ \mathcal{O}\left({m}_b^{-3}\right) $$ O m b − 3 at leading order in α s , keeping the dependence on the hadron spin. For a polarized baryon we compute the distribution $$ \frac{d^2\Gamma}{dy\ d\cos {\theta}_P} $$ d 2 Γ dy d cos θ P , with y = 2 E γ / m b , E γ the photon energy and θ P the angle between the baryon spin vector and the photon momentum in the H b rest-frame. We discuss the correlation between the baryon and photon polarization, and show that effects of physics beyond the Standard Model can modify the photon polarization asymmetry. We also discuss a method to treat the singular terms in the photon energy spectrum obtained by the OPE.

10.1007/jhep10(2023)147

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Citations (1)

Long distance effects inb→s exclusive decays

Zeitschrift für Physik C (1990)

Pietro Colangelo G. Nardulli N. Paver Riazuddin

Hamiltonian (control theory)

10.1007/bf01556270

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Citations (51)

QCD and Effective Locality

AIP conference proceedings (2010)

H. M. Fried Y. Gabellini T. Grandou Y.‐M. Sheu M. Gattobigio

In a recent paper it was shown how quark scattering in a quenched, eikonal model led to a momentum-transfer dependent amplitude expressed in terms of Halpern's functional integral; and how the requirement of manifest gauge invariance converted that functional integral into a local integral, capable of being evaluated with precision by a finite set of numerical integrations. We here prove that this property of "effective locality" holds true for all quark processes, without approximation and without exception.

10.1063/1.3536553

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Citations (3)

Improved bound on WR mass in left-right symmetric models from K0 mixing

Physics Letters B (1991)

Pietro Colangelo G. Nardulli

10.1016/0370-2693(91)91377-8

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Citations (10)

Weak Radiative Hyperon Decays in Quark Model

AIP conference proceedings (2007)

В.С. Замиралов Pietro Colangelo D. Creanza Fulvia De Fazio R. A. Fini

Weak radiative hyperon decays are considered in the framework of a quark model. The phenomenological model includes 1‐quark transitions with the effective sdγ‐vertex and 2‐quark ones with the W‐exchange s+u→u++d+γ and turns out to describe well the data and gives predictions for asymmetry of the decays Λ→n+γ and Ξ→Σ+γ.

10.1063/1.2823883

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Citations (1)

Correlation lengths and finite size effects for the Yang-Mills SU(2) lattice theory

Physics Letters B (1987)

Pietro Colangelo

Special unitary group

Lattice (music)

Coupling constant

Yang–Mills theory

Lattice constant

Length scale