Matching of fracture functions for SIDIS in target fragmentation region

In the target fragmentation region of Semi-Inclusive Deep Inelastic Scattering, the diffractively produced hadron has small transverse momentum. If it is at order of ΛQCD, it prevents to make predictions with the standard collinear factorization. However, in this case, differential cross-sections can be predicted by the factorization with fracture functions, diffractive parton distributions. If the transverse momentum is much larger than ΛQCD but much smaller than Q which is the virtuality of the virtual photon, both factorizations apply. In this case, fracture functions can be factorized with collinear parton distributions and fragmentation functions. We study the factorization up to twist-3 level and obtain gauge invariant results. They will be helpful for modeling fracture functions and useful for resummation of large logarithm of the transverse momentum appearing in collinear factorization.

Dynamical Properties of Baryons

The internal structure of composite particles is conveniently described in terms of form factors (FFs)—these are experimentally accessible in annihilation and scattering of elementary reactions, and are theoretically calculable by all models that describe the properties of particles. FFs depend only on one kinematical variable, q2. This is the four-momentum transferred by the virtual photon that carries the interaction. Important developments in accelerator and detector techniques have brought impressive advances, both by extending the kinematical region and by reaching a higher precision. A critical review on the underlying methods and findings in polarized and unpolarized experiments is presented. The unique role played by polarization in determining the ratio of electric to magnetic form factors in the space-like region, and the extraction of individual form factors in the whole kinematical region, are described. Recent results at electron accelerators and electron–positron colliders confirm the existence of periodical structure in the annihilation cross section. We suggest a global framework which describes the dynamical structure of charge distribution in baryons, in order to build a coherent view of the creation and annihilation of baryonic matter.

Saturation effects in SIDIS at very forward rapidities

Using the dipole picture for electron-nucleus deep inelastic scattering at small Bjorken x, we study the effects of gluon saturation in the nuclear target on the cross-section for SIDIS (single inclusive hadron, or jet, production). We argue that the sensitivity of this process to gluon saturation can be enhanced by tagging on a hadron (or jet) which carries a large fraction z ≃ 1 of the longitudinal momentum of the virtual photon. This opens the possibility to study gluon saturation in relatively hard processes, where the virtuality Q2 is (much) larger than the target saturation momentum $$ {Q}_s^2 $$ Q s 2 , but such that z(1 − z)Q2 ≲ $$ {Q}_s^2 $$ Q s 2 . Working in the limit z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we predict new phenomena which would signal saturation in the SIDIS cross-section. For sufficiently low transverse momenta k⊥ ≪ Qs of the produced particle, the dominant contribution comes from elastic scattering in the black disk limit, which exposes the unintegrated quark distribution in the virtual photon. For larger momenta k⊥ ≳ Qs, inelastic collisions take the leading role. They explore gluon saturation via multiple scattering, leading to a Gaussian distribution in k⊥ centred around Qs. When z(1 − z)Q2 ≪ Q2, this results in a Cronin peak in the nuclear modification factor (the RpA ratio) at moderate values of x. With decreasing x, this peak is washed out by the high-energy evolution and replaced by nuclear suppression (RpA< 1) up to large momenta k⊥ ≫ Qs. Still for z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we also compute SIDIS cross-sections integrated over k⊥. We find that both elastic and inelastic scattering are controlled by the black disk limit, so they yield similar contributions, of zeroth order in the QCD coupling.

On the Electromagnetic Vacuum Origins of Dark Energy, Dark Matter, and Astrophysical Jets

We use a semiclassical version of the Nexus paradigm of quantum gravity in which the quantum vacuum at large scales is dominated by the second quantized electromagnetic field to demonstrate that a virtual photon field can affect the geometric evolution of Einstein manifolds or Ricci solitons. This phenomenon offers a cogent explanation of the origins of astrophysical jets, the cosmological constant, and a means of detecting galactic dark matter.

A Factor That Comes in Error Which Is Neglected

This research is about a common factor that causes an error in every experiment we perform in laboratories to find out the value of a certain physical quantity. That factor arises when we difference the theoretical value and the experimental value for the same experiment which most probably I have considered as an effect of “something” which is undiscovered till the date. In this paper, there’ll be the inclusion of procedures and observations regarding the birth of that common factor as well as discussion on what might be the cause of that factor from an experimental as well as a theoretical approach. This research paper might unify physics as there is the inclusion of a virtual photon which might have obstructed every experiments one performs. Not only a virtual photon, but it might be any elementary particles or a new elementary particle which hasn’t been discovered till the date. The tentative value of error which comes in the figure of charge of an electron that propelled me to think on virtual photon. By getting raw data of experiments and then differentiating it with respect to theoretical values, we get an error by a slightest of margin. On doing the same procedure for numerous experiments, an error which is multiple of charge of an electron was obtained. Thus, this error is what the research paper is all about. It explains what that error is, why there is an error, and how the error is identified in almost all experiments we perform in laboratories.

A Factor That Comes in Error Which Is Neglected

This research is about a common factor that causes an error in every experiment we perform in laboratories to find out the value of a certain physical quantity. That factor arises when we difference the theoretical value and the experimental value for the same experiment which most probably I have considered as an effect of “something” which is undiscovered till the date. In this paper, there’ll be the inclusion of procedures and observations regarding the birth of that common factor as well as discussion on what might be the cause of that factor from an experimental as well as a theoretical approach. This research paper might unify physics as there is the inclusion of a virtual photon which might have obstructed every experiments one performs. Not only a virtual photon, but it might be any elementary particles or a new elementary particle which hasn’t been discovered till the date. The tentative value of error which comes in the figure of charge of an electron that propelled me to think on virtual photon. By getting raw data of experiments and then differentiating it with respect to theoretical values, we get an error by a slightest of margin. On doing the same procedure for numerous experiments, an error which is multiple of charge of an electron was obtained. Thus, this error is what the research paper is all about. It explains what that error is, why there is an error, and how the error is identified in almost all experiments we perform in laboratories.

Strong constraints on the b → sγ photon polarisation from B0 → K*0e+e− decays

An angular analysis of the B0 → K*0e+e− decay is performed using a data sample corresponding to an integrated luminosity of 9 fb−1 of pp collisions collected with the LHCb experiment. The analysis is conducted in the very low dielectron mass squared (q2) interval between 0.0008 and 0.257 GeV2, where the rate is dominated by the B0 → K*0γ transition with a virtual photon. The fraction of longitudinal polarisation of the K*0 meson, FL, is measured to be FL = (4.4 ± 2.6 ± 1.4)%, where the first uncertainty is statistical and the second systematic. The $$ {A}_{\mathrm{T}}^{\mathrm{Re}} $$ A T Re observable, which is related to the lepton forward-backward asymmetry, is measured to be $$ {A}_{\mathrm{T}}^{\mathrm{Re}} $$ A T Re = −0.06 ± 0.08 ± 0.02. The $$ {A}_{\mathrm{T}}^{(2)} $$ A T 2 and $$ {A}_{\mathrm{T}}^{\mathrm{Im}} $$ A T Im transverse asymmetries, which are sensitive to the virtual photon polarisation, are found to be $$ {A}_{\mathrm{T}}^{(2)} $$ A T 2 = 0.11 ± 0.10 ± 0.02 and $$ {A}_{\mathrm{T}}^{\mathrm{Im}} $$ A T Im = 0.02 ± 0.10 ± 0.01. The results are consistent with Standard Model predictions and provide the world’s best constraint on the b → sγ photon polarisation.

Dielectrons and Direct Virutal Photons at RHIC-STAR

Electromagnetic probes are unique probes of the hot and dense medium cre- ated in relativistic heavy-ion collisions due to their minimal interactions with the partonic and hadronic medium. They can be produced at all stages of a collision, thus they provide unique ways to study the medium properties of the whole collision evolution. We present the dielectron invariant mass spectrum at √sNN = 27, 39, 39, and 62.4 GeV. Comparing to hadronic cocktail simulation, significant excesses of dielectron invariant mass spectrum at low mass are observed. The direct virtual photon invariant yields derived from the low-mass e+e− continuum in Au+Au collisions at √sNN = 200 GeV is presented and the excesses from thermal photons in low transverse momentum (pT) have been observed. Model calculations can simultaneously describe both dielectron low mass excesses and direct virtual photon low pT excesses.