scholarly journals Hypernuclei in halo/cluster effective field theory

2016 ◽  
Vol 25 (05) ◽  
pp. 1641005 ◽  
Author(s):  
Shung-Ichi Ando

The light double [Formula: see text] hypernuclei, [Formula: see text] and [Formula: see text], are studied as three-body [Formula: see text] and [Formula: see text] cluster systems in halo/cluster effective field theory at leading order. We find that the [Formula: see text] system in spin-0 channel does not exhibit a limit cycle whereas the [Formula: see text] system in spin-1 channel and the [Formula: see text] system in spin-0 channel do. The limit cycle is associated with the formation of bound states, known as Efimov states, in the unitary limit. For the [Formula: see text] system in the spin-0 channel we estimate the scattering length [Formula: see text] for [Formula: see text]-wave [Formula: see text] hyperon–hypertriton scattering as [Formula: see text][Formula: see text]fm. We also discuss that studying the cutoff dependences in the [Formula: see text] and [Formula: see text] systems, the bound state of [Formula: see text] is not an Efimov state but formed due to a high energy mechanism whereas that of [Formula: see text] may be regarded as an Efimov state.

Author(s):  
Subhaditya Bhattacharya ◽  
José Wudka

Standard Model (SM) of particle physics has achieved enormous success in describing the interactions among the known fundamental constituents of nature, yet it fails to describe phenomena for which there is very strong experimental evidence, such as the existence of dark matter, and which point to the existence of new physics not included in that model; beyond its existence, experimental data, however, have not provided clear indications as to the nature of that new physics. The effective field theory (EFT) approach, the subject of this review, is designed for this type of situations; it provides a consistent and unbiased framework within which to study new physics effects whose existence is expected but whose detailed nature is known very imperfectly. We will provide a description of this approach together with a discussion of some of its basic theoretical aspects. We then consider applications to high-energy phenomenology and conclude with a discussion of the application of EFT techniques to the study of dark matter physics and its possible interactions with the SM. In several of the applications we also briefly discuss specific models that are ultraviolet complete and may realize the effects described by the EFT.


2013 ◽  
Vol 21 ◽  
pp. 153-154
Author(s):  
CHUAN-TSUNG CHAN ◽  
SHOICH KAWAMOTO ◽  
DAN TOMINO

It is known that infinitely many linear relations among string scattering amplitudes appear in high energy limit. These linear relations would imply a symmetry structure that is not manifest before taking the high energy limit. Motivated by this observation, we study an effective field theory of massive spin-2 and spin-1 particles, and try to understand what kind of structure reproduces the linear relations among the amplitudes of bosonic open string.


2013 ◽  
Vol 331 ◽  
pp. 24-50 ◽  
Author(s):  
Michelle Pine ◽  
Dean Lee

2016 ◽  
Vol 25 (05) ◽  
pp. 1641007 ◽  
Author(s):  
Manuel Pavón Valderrama

Effective field theories are the most general tool for the description of low energy phenomena. They are universal and systematic: they can be formulated for any low energy systems we can think of and offer a clear guide on how to calculate predictions with reliable error estimates, a feature that is called power counting. These properties can be easily understood in Wilsonian renormalization, in which effective field theories are the low energy renormalization group evolution of a more fundamental — perhaps unknown or unsolvable — high energy theory. In nuclear physics they provide the possibility of a theoretically sound derivation of nuclear forces without having to solve quantum chromodynamics explicitly. However there is the problem of how to organize calculations within nuclear effective field theory: the traditional knowledge about power counting is perturbative but nuclear physics is not. Yet power counting can be derived in Wilsonian renormalization and there is already a fairly good understanding of how to apply these ideas to non-perturbative phenomena and in particular to nuclear physics. Here we review a few of these ideas, explain power counting in two-nucleon scattering and reactions with external probes and hint at how to extend the present analysis beyond the two-body problem.


2014 ◽  
Vol 35 ◽  
pp. 1460431
Author(s):  
THOMAS MEHEN

This talk summarizes recent developments in quarkonium spectroscopy. I comment on the relation between the Zb(10610) and Zb(10650) and recently observed Zc(3900) and Zc(4025) states. Then I discuss a number of calculations using non-relativistic effective field theory for the X(3872), Zb(10610), and Zb(10650), under the assumption that these are shallow molecular bound states of charm or bottom mesons.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Joshua Rosaler

AbstractThe earliest formulation of the Higgs naturalness argument has been criticized on the grounds that it relies on a particular cutoff-based regularization scheme. One response to this criticism has been to circumvent the worry by reformulating the naturalness argument in terms of a renormalized, regulator-independent parametrization. An alternative response is to deny that regulator dependence poses a problem for the naturalness argument, because nature itself furnishes a particular, physically correct regulator for any effective field theory (EFT) in the form of that EFT’s physical cutoff, together with an associated set of bare parameters that constitute the unique physically preferred “fundamental parameters” of the EFT. Here, I argue that both lines of defense against the initial worry about regulator dependence are flawed. I argue that reformulation of the naturalness argument in terms of renormalized parameters simply trades dependence on a particular regularization scheme for dependence on a particular renormalization scheme, and that one or another form of scheme dependence afflicts all formulations of the Higgs naturalness argument. Concerning the second response, I argue that the grounds for suspending the principle of regularization or renormalization scheme independence in favor of a physically preferred parametrization are thin; the assumption of a physically preferred parametrization, whether in the form of bare “fundamental parameters” or renormalized “physical parameters,” constitutes a theoretical idle wheel in generating the confirmed predictions of established EFTs, which are invariably scheme-independent. I highlight certain features of the alternative understanding of EFTs, and the EFT-based approach to understanding the foundations of QFT, that emerges when one abandons the assumption of a physically preferred parametrization. I explain how this understanding departs from several dogmas concerning the mathematical formulation and physical interpretation of EFTs in high-energy physics.


2019 ◽  
Vol 202 ◽  
pp. 01005 ◽  
Author(s):  
Jaume Tarrús Castellà

We report on an effective field theory (EFT) description of exotic quarkonia as bound states on the spectrum of hybrid and tetraquarks static energies. We provide expressions for hybrid and tetraquarks static energies in terms of Wilson loops. The former have been computed in quenched lattice calculations but the latter are yet unavailable. From the few simulations with dynamical light-quarks we argue that the overall picture from hybrid static energies does not change but additional states, such as heavy meson pairs, need to be considered for a full description. In this EFT framework for quarkonium hybrids, we report on recent results for mixing with standard quarkonium, spin-dependent contributions, and semi-inclusive decays.


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