scholarly journals Quantum information approach to high energy interactions

2021 ◽  
Vol 380 (2216) ◽  
Author(s):  
Dmitri E. Kharzeev
Keyword(s):  
Density Matrix ◽  
Light Cone ◽  
Particle Physics ◽  
Evolution Equations ◽  
Spin Asymmetry ◽  
Entanglement Entropy ◽  
Parton Model ◽  
High Energy ◽  
Wave Functions ◽  
Fock State

High energy hadron interactions are commonly described by using a probabilistic parton model that ignores quantum entanglement present in the light-cone wave functions. Here, we argue that since a high energy interaction samples an instant snapshot of the hadron wave function, the phases of different Fock state wave functions cannot be measured—therefore the light-cone density matrix has to be traced over these unobservable phases. Performing this trace with the corresponding U ( 1 ) Haar integration measure leads to ‘Haar scrambling’ of the density matrix, and to the emergence of entanglement entropy. This entanglement entropy is determined by the Fock state probability distribution, and is thus directly related to the parton structure functions. As proposed earlier, at large rapidity η the hadron state becomes maximally entangled, and the entanglement entropy is S E ∼ η according to QCD evolution equations. When the phases of Fock state components are controlled, for example in spin asymmetry measurements, the Haar average cannot be performed, and the probabilistic parton description breaks down. This article is part of the theme issue ‘Quantum technologies in particle physics’.

scholarly journals Nonperturbative approach to the parton model

2016 ◽  
Vol 31 (06) ◽  
pp. 1650016 ◽  
Author(s):  
Yu. A. Simonov
Keyword(s):  
Nonperturbative Effects ◽  
Parton Model ◽  
String Tension ◽  
High Energy ◽  
Wave Functions ◽  
Parton Distributions ◽  
Text String ◽  
Preliminary Discussion ◽  
High Energy Scattering

In this paper, the nonperturbative parton distributions, obtained from the Lorentz contracted wave functions, are analyzed in the formalism of many-particle Fock components and their properties are compared to the standard perturbative distributions. We show that the collinear and IR divergencies specific for perturbative evolution treatment are absent in the nonperturbative version, however for large momenta [Formula: see text] (string tension), the bremsstrahlung kinematics is restored. A preliminary discussion of possible nonperturbative effects in DIS and high energy scattering is given, including in particular a possible role of multihybrid states in creating ridge-type effects.

scholarly journals SINGLE SPIN ASYMMETRY IN HIGH ENERGY QCD

2012 ◽  
Vol 20 ◽  
pp. 177-186
Author(s):  
YURI V. KOVCHEGOV ◽  
MATTHEW D. SIEVERT
Keyword(s):  
Wave Function ◽  
Light Cone ◽  
Spin Asymmetry ◽  
Production Cross ◽  
High Energy ◽  
Transverse Spin ◽  
Proton Proton ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Polarized Proton

We present the first steps in an effort to incorporate the physics of transverse spin asymmetries into the saturation formalism of high energy QCD. We consider a simple model in which a transversely polarized quark scatters on a proton or nuclear target. Using the light-cone perturbation theory the hadron production cross section can be written as a convolution of the light-cone wave function squared and the interaction with the target. To generate the single transverse spin asymmetry (STSA) either the wave function squared or the interaction with the target has to be T-odd. In this work we use the lowest-order q → q G wave function squared, which is T-even, generating the STSA from the T-odd interaction with the target mediated by an odderon exchange. We study the properties of the obtained STSA, some of which are in qualitative agreement with experiment: STSA increases with increasing projectile xF and is a non-monotonic function of the transverse momentum kT. Our mechanism predicts that the quark STSA in polarized proton–nucleus collisions should be much smaller than in polarized proton–proton collisions. We also observe that the STSA for prompt photons due to our mechanism is zero within the accuracy of the approximation.

DGLAP and BFKL Equations now

2003 ◽  
Vol 18 (supp01) ◽  
pp. 68-90 ◽  
Author(s):  
L. N. Lipatov
Keyword(s):  
Evolution Equations ◽  
Gauge Theories ◽  
Parton Model ◽  
High Energy ◽  
Effective Theory ◽  
Dglap Evolution ◽  
Regge Trajectories ◽  
Supersymmetric Gauge ◽  
Energy Hadron ◽  
Inelastic Processes

The s and t-channel approaches to the high energy hadron scattering are reviewed. The parton model is applied to describe the high energy and deep-inelastic processes. In QCD the parton picture leads to the DGLAP evolution equations for the parton distributions. The gluon and quark are shown to lie on their Regge trajectories. The integrability properties of the effective theory for the high energy QCD in the multi-colour limit are outlined. The Baxter - Sklyanin representation for the wave function of the composite colourless states is formulated. Next-to-leading corrections to the BFKL equation in QCD and supersymmetric gauge theories are discussed. The effective action for the gluon and quark integrations local in the parton rapidities is presented.

PARTICLE PRODUCTION AT COLLIDER ENERGIES

1989 ◽  
Vol 04 (07) ◽  
pp. 1527-1680 ◽  
Author(s):  
CHRISTOPH GEICH-GIMBEL
Keyword(s):  
Particle Physics ◽  
Particle Production ◽  
Cosmic Ray ◽  
Parton Model ◽  
High Energy ◽  
High Energy Particle ◽  
Final State ◽  
Long Range Correlations ◽  
Vector Bosons ◽  
Order Of Magnitude

High energy particle physics, which has been trying to understand and to devise new laws governing nature at per particle energies far beyond everyday energies, has entered a new episode. Having surpassed the ‘low energy’ regime, where (s channel) resonance production dominantly projects onto the final state, very interesting features of the strong interaction arose at c.m. energies in the tens of GEV range, as found at the CERN Intersecting Storage Rings (ISR). One recalls the onset of hard scattering processes, which was understood as a scattering between constituents of the nucleon, hence supporting the Quark Parton Model (QPM). Surprisingly enough the total cross section started to rise again, when it was initially believed to have reached a constant value, suggesting an asymptotia. Furthermore correlations among the final state particles produced were observed, and especially long range correlations, which must reflect dynamical laws. The advent of the CERN [Formula: see text] Collider, with c.m. energies up to 900 GeV, representing a step of more than an order of magnitude in the energy available, puts one into a position to test more directly many of these ‘new’ things and to prove the existence of the elusive intermediate vector bosons W± and Z, thus unifying weak and electromagnetic interactions. Finally a bridge to cosmic ray results at extreme energies may be provided. Naturally quite a lot of new unanswered questions will emerge in the investigations of Collider data, since new regions bring new surprises, but this possibility should be regarded as a means of gaining new insights, rather than as a disturbance of hitherto believed regularities, of which some inevitably fail. In this spirit the following article is written.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

scholarly journals Target space entanglement in quantum mechanics of fermions and matrices

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Sotaro Sugishita
Keyword(s):  
Mutual Information ◽  
Ground State ◽  
Entanglement Entropy ◽  
Algebraic Approach ◽  
Upper Bounds ◽  
Wave Functions ◽  
Target Space ◽  
Single Interval ◽  
Area Law ◽  
Formula Expression

Abstract We consider entanglement of first-quantized identical particles by adopting an algebraic approach. In particular, we investigate fermions whose wave functions are given by the Slater determinants, as for singlet sectors of one-matrix models. We show that the upper bounds of the general Rényi entropies are N log 2 for N particles or an N × N matrix. We compute the target space entanglement entropy and the mutual information in a free one-matrix model. We confirm the area law: the single-interval entropy for the ground state scales as $$ \frac{1}{3} $$ 1 3 log N in the large N model. We obtain an analytical $$ \mathcal{O}\left({N}^0\right) $$ O N 0 expression of the mutual information for two intervals in the large N expansion.

scholarly journals High-energy operator product expansion at sub-eikonal level

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Giovanni Antonio Chirilli
Keyword(s):  
Operator Product Expansion ◽  
Evolution Equations ◽  
Energy Operator ◽  
High Energy ◽  
Structure Functions ◽  
Distribution Functions ◽  
Impact Factors ◽  
Operator Product ◽  
The Impact ◽  
New Distribution

Abstract The high energy Operator Product Expansion for the product of two electromagnetic currents is extended to the sub-eikonal level in a rigorous way. I calculate the impact factors for polarized and unpolarized structure functions, define new distribution functions, and derive the evolution equations for unpolarized and polarized structure functions in the flavor singlet and non-singlet case.

scholarly journals REVIEW OF THE PHENOMENOLOGY OF NONCOMMUTATIVE GEOMETRY

2004 ◽  
Vol 19 (02) ◽  
pp. 179-204 ◽  
Author(s):  
I. HINCHLIFFE ◽  
N. KERSTING ◽  
Y. L. MA
Keyword(s):  
Electric Dipole ◽  
Particle Physics ◽  
Extra Dimensions ◽  
Linear Collider ◽  
Dipole Moments ◽  
High Energy ◽  
Low Energy ◽  
Electric Dipole Moments ◽  
The Status ◽  
High Energy Scattering

We present a pedagogical review of particle physics models that are based on the noncommutativity of space–time, [Formula: see text], with specific attention to the phenomenology these models predict in particle experiments either in existence or under development. We summarize results obtained for high energy scattering such as would occur, for example, in a future e+e-linear collider with [Formula: see text], as well as low energy experiments such as those pertaining to elementary electric dipole moments and other CP violating observables, and finally comment on the status of phenomenological work in cosmology and extra dimensions.

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