Indication on the process dependence of the Sivers effect.
Leonard Gamberg1, Zhong-Bo Kang2, Alexei Prokudin3
1Division of Science, Penn State University Berks, Reading, Pennsylvania 19610, USA.
Physical Review Letters
|August 29, 2014
Summary
We analyzed spin asymmetry in proton-proton collisions, finding consistency with Sivers effect predictions. This suggests the Sivers effect is process-dependent, impacting future high-energy physics research.
Area of Science:
- High Energy Physics
- Quantum Chromodynamics
- Spin Physics
Background:
- The Sivers effect describes the correlation between a parton's transverse momentum and the spin of a polarized hadron.
- Understanding the process dependence of the Sivers effect is crucial for interpreting experimental data in particle physics.
Purpose of the Study:
- To investigate the process dependence of the Sivers effect by comparing jet spin asymmetry data with Sivers functions.
- To explore the role of color gauge invariance in the Sivers effect.
Main Methods:
- Analysis of single inclusive jet production data from the AnDY experiment at RHIC.
- Comparison of experimental results with theoretical calculations incorporating initial-state and final-state interactions.
- Utilizing Sivers functions extracted from semi-inclusive deep inelastic scattering (SIDIS) experiments (HERMES, COMPASS).
Main Results:
- Calculated jet spin asymmetry is consistent with AnDY experimental data when using Sivers functions from SIDIS.
- This consistency provides the first indication of the Sivers effect's process dependence in these specific collision types.
- The study highlights the importance of initial-state and final-state interactions in theoretical models.
Conclusions:
- The Sivers effect exhibits process dependence, as evidenced by the agreement between jet production and SIDIS data.
- Color gauge invariance plays a key role in understanding this process dependence.
- Predictions are made for direct photon and Drell-Yan spin asymmetries to further test the Sivers effect's behavior in future experiments.
More Related Videos
08:35An Operant Intra-/Extra-dimensional Set-shift Task for Mice
Published on: January 22, 2016
13.9K
09:01A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance
Published on: May 7, 2014
9.5K
Related Concept Videos
01:14Reversible and Irreversible Processes
4.3K
The thermodynamic processes can be classified into reversible and irreversible processes. The processes that can be restored to their initial state are called reversible processes. It is only possible if the process is in quasi-static equilibrium, i.e., it takes place in infinitesimally small steps, and the system remains at equilibrium However, these are ideal processes and do not occur naturally. An ideal system undergoing a reversible process is always in thermodynamic equilibrium within...
4.3K
01:19Types of Functions II
370
Trigonometric and exponential functions are essential mathematical tools used to model distinct types of real-world behavior, particularly in periodic and growth-related phenomena. These functions extend the capabilities of basic algebraic models by capturing recurring cycles and rapid changes across various scientific and engineering contexts.Trigonometric functions, such as sine and cosine, are particularly effective for representing periodic phenomena. Their cyclic behavior makes them...
370
01:28Types of Functions III
406
Logarithmic and piecewise functions play central roles in mathematical modeling, particularly when capturing nonlinear or segmented behaviors in real-world phenomena. Although these functions differ fundamentally in structure and application, both serve to represent complex relationships in simplified mathematical terms.A logarithmic function is defined as the inverse of an exponential function, expressed as These functions grow quickly for small values of x but slow down as x increases,...
406
01:19Cyclic Processes And Isolated Systems
2.6K
A thermodynamic system with zero heat exchange and work is an isolated system. For these systems, the internal energy remains constant.
In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state.
Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each...
In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state.
Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each...
2.6K
01:23Continuity of a Function
392
A function is continuous at a point a if three conditions are met: the function is defined at a, the limit of the function as x approaches a exists, and this limit equals the function’s value. Mathematically, this is written asThis definition ensures the graph of the function does not exhibit any breaks, holes, or jumps at that point. Discontinuities occur when any of these conditions fail. A removable discontinuity exists when the two-sided limit exists but the function is either...
392
01:27Derivatives of Simple Functions
476
Derivatives quantify the rate of change of a function and can be interpreted geometrically as the slope of a straight line or the slope of a tangent line to a curve at a given point. In the context of a roller coaster, the derivative of the function describing the track’s horizontal position provides a mathematical description of how steep the path is at any location along the ride.Constant and Linear PathsA horizontal segment of a roller coaster can be modeled by a constant function,...
476