The criticisms in manuscript arXiv:0803.4371 do not change the renormalization group equation for the "$\vlowk$" interaction nor do they affect any results in the literature. Several other potentially misleading statements about low-momentum interactions are also addressed.
In a recent paper [Phys.\ Rev.\ C{\bf 49}, 2142 (1994)], Haberzettl presented cluster N-body equations for arbitrarily large systems of nucleons and mesons. Application to the three-nucleon system is claimed to yield a new kind of three-nucleon force. We demonstrate that these three-nucleon equations contain double counting.
Authors of Phys. Rev. C 60, 062201 (1999) presented a calculation of the electromagnetic form factors of the nucleon using a diquark ansatz in the relativistic three-quark Faddeev equations. In this Comment it is pointed out that the calculations of these form factors stem from a three-quark bound state current that contains overcounted contributions. The corrected expression for the three-quark bound state current is derived.
Methods of analysis of nucleon-nucleus scattering data have progressed markedly over the past 50 years, yet many analyses of scattering data still use prescriptions specified at various stages of that progress. But the assumptions made or inherent in those analyses are poorly justified and most are no longer necessary to facilitate evaluations. We investigate some of those assumptions and highlight deficiencies and the uncertainties they may make in data analyses.
The present paper is written in response to the comment of M. R. Hadizadeh et. al on our original paper "Solution of the Specific Model of Five-body Problem to Investigate the Effective Alpha-Nucleon Interaction in a Partial-Wave analysis" [Acta Physica Polonica B, 48, 1279 (2017)]. In this paper we present our clarifications and statements on the authors of the comment arguments about of the accuracy of the procedure in solution of simple five- and four-body problems. In this regard our arguments turn out to be very efficient mainly discussed from the authors misunderstanding of the issues di…
The article of Pastore et al, while proposing an interesting and potentially useful approach for the generalisation of Quantum Monte Carlo techniques to the treatment of the nuclear electromagnetic response, features an incorrect and misleading discussion of y-scaling. The response to interactions with transversely polarised virtual photons receives sizeable contributions from non-scaling processes, in which the momentum transfer is shared between two nucleons. It follows that, contrary to what is stated by the the authors, y-scaling in the transverse channel is accidental.
In a recent Physical Review Letter, Kondo and Morimatsu present a QCD sum rule calculation of nucleon-nucleon scattering lengths. They also relate the empirical scattering lengths to the nucleon mass shift in nuclear matter to cast doubt on the "linear density approximation." In this Comment, we point out flaws in both parts of their analysis and draw very different conclusions.
A general expression for the $π-N$ and $π-Δ$ scattering lengths is derived in the framework of a microscopic calculation. Annihilation, negative energy wave-functions and spontaneous chiral symmetry are included consistently. The point-like limit is used to calculate the scattering lengths.
We comment on the paper of Gellas et al, nucl-th/0002027, in which heavy baryon chiral perturbation theory results for the spin polarisabilities of the nucleon are given. That paper uses a definition which is different from the one used in papers by us, hep-ph/9908526, hep-ph/9909442 and hep-ph/0002133. In this comment we show that it is the latter definition, and not that of Gellas et al, that should be compared with the values of the polarisabilities extracted from dispersion relation analyses.
Recently, Fearing (nucl-th/9710061) has argued that, as a matter of principle, proton-proton bremsstrahlung can yield no more information about the off-shell properties of the nucleon-nucleon interaction than can already be deduced from the on-shell properties. In this note we challenge Fearing's conclusion.
In \cite{Bodek:2020wbk} Bodek and Cai have tried to extract the potentials for nucleons and $Δ$ resonances from electron-nucleus inclusive scattering data. They find that the $Δ$ potential is considerably more attractive than that of the nucleons. This result is at variance with the results of a multitude of analyses of (e,A) and ($γA$) interactions, performed about 35 years ago.
We reply to the Comment of Brodsky and Gardner on our paper "New limits on intrinsic charm in the nucleon from global analysis of parton distributions" [Phys. Rev. Lett. 114, 082002 (2015)]. We address a number of incorrect claims made about our fitting methodology, and elaborate how global QCD analysis of all available high-energy data provides no evidence for a large intrinsic charm component of the nucleon.
In a recent Letter, Alberg and Miller presented a calculation of the pion contributions to the self-energy of the nucleon computed from a pseudoscalar (PS) pion-nucleon interaction, with the claim that the result would be equivalent to that with the pseudovector (PV) form. We demonstrate that the PV and PS pion-nucleon couplings do in fact lead to different results for the self-energy. In particular, for the model-independent, leading nonanalytic behavior of the self-energy, the PV theory yields the well-known m_π^3 dependence in the chiral limit, while the PS interaction involves an additiona…
In their Comment, Borasoy et al. [arXiv:hep-ph/0512279], criticize our results [PRL 95 (2005) 172502] that accommodate both scattering data and the new accurate measurement by DEAR of the shift and width of kaonic hydrogen. In our calculations we have employed unitary chiral perturbation theory (UCHPT). We discuss why their arguments are irrelevant or do not hold.
It has recently been claimed by Oller et al. [PRL 95 (2005) 172502] that the DEAR kaonic hydrogen data can be reconciled with K^- p scattering data in a chiral unitary approach. In this comment we demonstrate that the proposed solution violates fundamental principles of scattering theory.
In this comment, we address a number of erroneous discussions and conclusions presented in a recent preprint by the HALQCD collaboration, arXiv:1703.07210. In particular, we demonstrate that lattice QCD determinations of bound states at quark masses corresponding to a pion mass of $m_π= 806$ MeV are robust, and that the phases shifts extracted by the NPLQCD collaboration for these systems pass all of the 'sanity checks' introduced in arXiv:1703.07210.
The value of $59 \pm 12$ MeV for the pion-nucleon ($πN$) $Σ$ term, which Stahov, Clement, and Wagner recently extracted from the differential cross sections (DCSs) of the CHAOS Collaboration, does not match well the expectation of an enhanced (more positive) isoscalar component in the $πN$ interaction at low energies, which the rest of the modern (meson-factory) data favour. However, we have already demonstrated that the angular distribution of the CHAOS $π^+ p$ DCSs is not compatible in shape with the rest of the modern low-energy $π^+ p$ data. This problem must be addressed and resolved by t…
We develop a method for constructing the Heavy Baryon Chiral Perturbation Theory Lagrangian (L_{HBChPT}), to a given chiral order, within HBChPT. We work within SU(2) theory, with only the pion field interacting with the nucleon. The main difficulties, which are solved, are to develop techniques for implementing charge conjugation invariance, and for taking the nucleon on shell, both within the nonrelativistic formalism. We obtain complete lists of independent terms in L_{HBChPT} through O(q^3) for off- shell nucleons. Then, eliminating equation-of-motion (eom) terms at the relativistic and no…
We discuss in detail the derivation of the leading four-nucleon force in chiral effective field theory using the method of unitary transformation. The resulting four-nucleon force is given in both momentum and configuration space. It does not contain any unknown parameters and can be used in few- and many-nucleon studies.
Within the $σ-ω$ model of coupled nucleon-meson systems, a generalized relativistic Lenard--Balescu--equation is presented resulting from a relativistic random phase approximation (RRPA). This provides a systematic derivation of relativistic transport equations in the frame of nonequilibrium Green's function technique including medium effects as well as fluctuation effects. It contains all possible processes due to one meson exchange and special attention is kept to the off--shell character of the particles. As a new feature of many particle effects, processes are possible which can be interpr…
We derive the nucleon-nucleon interaction from the Skyrme model using second order perturbation theory and the dipole approximation to skyrmion dynamics. Unlike previous derivations, our derivation accounts for the non-trivial kinetic and potential parts of the skyrmion-skyrmion interaction lagrangian and how they couple in the quantum calculation. We derive the eight low energy interaction potentials and compare them with the phenomenological Paris model, finding qualitative agreement in seven cases.
Within the $σ-ω$ model of coupled nucleon-meson systems, a generalized relativistic Lenard--Balescu--equation is presented resulting from a relativistic random phase approximation (RRPA). This provides a systematic derivation of relativistic transport equations in the frame of nonequilibrium Green's function technique including medium effects as well as flucuation effects. It contains all possible processes due to one meson exchange and special attention is kept to the off--shell character of the particles. As a new feature of many particle effects, processes are possible which can be interpre…
We construct a complete list of O(q^4) terms directly within Heavy Baryon Chiral Perturbation Theory (HBChPT) in the absence of external fields and assuming isospin symmetry. In addition to a phase rule recently developed (NPA646, 343, '99), a variety of algebraic identities and reparameterization invariance, are used to ensure linear independence of the terms and their low energy coupling constants. We first construct O(q^4) terms terms for off-shell nucleons, and then perform the on-shell reduction, again within HBChPT. We discuss an application of the O(q^4) terms to the evaluation of the O…
We carefully examine all the four derivations of the renormalization group equation (RGE) for the so-called $\Vlk$ potential, given by Bogner, \textit{et. al.}[nucl-th/0111042]. Two derivations based on the ``semi-group composition law'' are shown to be unjustified, while the other two based on the completeness relation of the model space must be modified if there are bound states. It is however shown that the RGE is unchanged if the bound state wavefunctions in the reduced theory are required to have the same low-momentum components as those in the original theory. Several aspects of the $\Vl…
This paper summarizes our studies of the hypertriton and describes our findings on the hyperon-nucleon interaction, especially on the role of the $ΛN-ΣN$ coupling and the strengths of the $S$-wave $YN$ interactions. We briefly comment on our ongoing analyses with electromagnetic probes.
The main progress in the field of nucleon-nucleon (NN) potentials, which we have seen in recent years, is the construction of some very quantitative (high-quality/high-precision) NN potentials. These potentials will serve as excellent input for microscopic nuclear structure calculations and will allow for a systematic investigation of off-shell effects. After this enormous quantitative work, it is now time to re-think the NN problem in fundamental terms. We need a derivation of the nuclear force which observes Lorentz invariance and the symmetries of QCD.
We present two arguments indicating that the large value for the $ε_1$ mixing parameter at 50 MeV, which the Basel group extracted from their recent $A_{zz}$ measurement, may be incorrect. First, there are nucleon-nucleon (NN) potentials which predict the $ε_1$ at 50 MeV substantially below the Basel value and reproduce the Basel $A_{zz}$ data accurately. Second, the large value for $ε_1$ at 50 MeV proposed by the Basel group can only be explained by a model for the NN interaction which is very unrealistic (no $ρ$-meson and essentially a point-like $πNN$ vertex) and overpredicts the $ε_1$ in t…
In recent work, Hill and Paz apply the operator product expansion to forward doubly virtual Compton scattering. The resulting large-$Q^2$ form of the amplitude $W_1(0,Q^2)$ is compatible with the one we obtain by extrapolation of low-$Q^2$ results from a chiral effective field theory, providing support for our approach. That paper also presents a result for the two-photon contribution to the Lamb shift in muonic hydrogen that has a much larger uncertainty than in previous work. We show that this an overestimate arising from the inclusion of the proton pole term in the subtracted dispersion rel…
We discuss the effective field theory approach to nuclear phenomena with typical momentum below the pion mass. We particularly focus on the three body problem. In the $J=3/2$ channel,effective field theory is extremelly predictive and we are able to describe the nucleon-deuteron scattering amplitude at the percent level using only two parameters obtained from nucleon-nucleon scattering. We briefly comment onthe $J=1/2$ channel and the issues related to the non-perturbative renormalization of the three body force.
We point out two flaws in the recent test of nucleon-nucleon (NN) potentials conducted by Stoks and de Swart. First, in some cases, the neutron-proton ($np$) version of an NN potential was compared to the proton-proton ($pp$) data, which is improper and yields (large) $χ^2$ that are essentially meaningless. Second, for a proper test of the quantitative nature of a NN potential, it is insufficient to compare to $pp$ data only, since this leaves the T=0 potential untested. Thus, it can happen that the $pp$ version of a potential predicts the $pp$ data accurately, while the $np$ version of that s…
Relativistic Faddeev-Yakubovsky four-nucleon scattering equations are derived including a 3-body force. We present these equations in the momentum space representation. The quadratic integral equations using the iteration method, in order to obtain boosted potentials and 3-body force, are demonstrated.
We discuss the use of the low-momentum nucleon-nucleon NN interaction V-low-k in the derivation of the shell-model effective interaction and emphasize its practical value as an alternative to the Brueckner G-matrix method. We present some selected results of our current study of exotic nuclei around closed shells, which have been obtained starting from the CD-Bonn potential. We also show some results of calculations performed with different phase-shift equivalent NN potentials, and discuss the effect of changes in the cutoff momentum which defines the V-low-k potential.
Guided by history, we review the major developments concerning realistic nucleon-nucleon (NN) potentials since the pioneering work by Kuo and Brown on the effective nuclear interaction. Our main emphasis is on the physics underlying various models for the NN interaction developed over the past quarter-century. We comment briefly on how to test the quantitative nature of nuclear potentials properly. A correct calculation (performed by independent researchers) of the $χ^2$/datum for the fit of the world NN data yields 5.1, 3.7, and 1.9 for the Nijmegen, Paris, and Bonn potential, respectively. F…
The phase space structure of zero temperature Quarkyonic Matter is a Fermi sphere of Quark Matter, surrounded by a shell of Nucleonic Matter. We construct a quasi particle model of Quarkyonic Matter based on the constituent quark model, where the quark and nucleon masses are related by m_Q = m_N/N_c, and N_c is the number of quark colors. The region of occupied states is for quarks k_Q < k_F/N_c, and for nucleons k_F < k_N < k_F + Δ. We first consider the general problem of Quarkyonic Matter with hard core nucleon interactions. We then specialize to a quasi-particle model where the hard core n…
Dispersion relations provide a powerful tool to describe the low-energy structure of hadrons. We review the status of the strange vector form factors of the nucleon in dispersion theory. We also comment on open questions and the relation to chiral perturbation theory.
Weinberg's contributions to the power counting and derivation of few-nucleon forces in Chiral EFT are briefly recalled. Subsequent improvements are reviewed, concluding with the recent suggestion of a combinatorial enhancement.
It is argued by the author that the canonical form of the quark energy-momentum tensor with a partial derivative instead of the covariant derivative is the correct definition for the quark momentum and angular momentum fraction of the nucleon in covariant quantization. Although it is not manifestly gauge invariant, its matrix elements in the nucleon will be non-vanishing and are gauge invariant. We test this idea in the path-integral quantization by calculating correlation functions on the lattice with a gauge-invariant nucleon interpolation field and replacing the gauge link in the quark latt…
It is suggested in the paper by A.J. Chambers {\it et al.} (Phys. Rev. Lett. 118, 242001 (2017), arXiv:1703.01153) that the time-ordered current-curent correlator in the nucleon calculated on the lattice is to be identified as the forward Compton amplitude so that it is related to the sum of the even moments of the structure function as in the Minkowski space in the continuum. We point out two problems with this identification. First of all, the current-current correlator defined in the Euclidean space is not analytic everywhere on the rest of the complex $ν$ or $ω$ plane, besides the cuts on …
Weinstein, et. al [1] [PRL 106, 052301 (2011)] and Hen, et. al [2] [PRC 85, 047301 (2012)] observed a correlation between the EMC effect and the amount of short range correlated (SRC) pairs in nuclei which implies that quark distributions are different in SRC pairs as compared with free nucleons. Schmookler, et. al [3] [Nature 566, 354 (2019)] bolstered this by showing that the EMC data can be explained by a universal modification of the structure of nucleons in neutron-proton SRC pairs and presented the first data-driven extraction of this universal modification function (UMF). Arrington and …
The critics of P. Lipavsky on the derivation of conservation laws including gradient corrections is refuted since his counterexample is based on a mathematical error. Instead, the derived conservation laws for density, momentum and energy remain valid even without using the objected relation. Only for the entropy local terms are missing which vanish under integration.
We introduce a momentum subtraction scheme which obeys the power counting of Kaplan, Savage, and Wise (KSW), developed for systems with large scattering lengths, $a$. Unlike the power divergence subtraction scheme, coupling constants in this scheme obey the KSW scaling for all $μ_R > 1/a$. We comment on the low-energy theorems derived by Cohen and Hansen. We conclude that there is no obstruction to using perturbative pions for momenta $p>m_π$.
We discuss the stability of atoms and nucleons in the presence of multidimensional gravity characterized by the unified energy scale 1TeV. We point out that the multidimensional gravitational attraction can create additional bound states deep inside of atomic and nucleon constituents. These states would be characterized by sizes comparable to the TeV scale distance. We show that shallow gravity induced bound states between an electron and a quark are ruled out, because collapse processes in atoms to such bound states would occur on time scales which are in contradiction to current data on the …