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Posts Tagged ‘heavy-ion’


NPP Seminar by Xiaodong Jiang (LANL)

October 25th, 2014 by geurts

Date: Tuesday November 4, 2014 at noon
Location: 223 Herman Brown Hall, Rice University

Title: Left-right bias in high energy polarized e+n, p+p and p+A collisions
Speaker:Xiaodong Jiang (LANL)

Abstract: Over the last three decades, large single-spin asymmetries have been observed in high energy polarized p?+p?hadron+X reactions on transversely polarized protons. According to perturbative QCD, this type of parity-conserving left-right asymmetry should be very small if produced from collinear quarks. However, when transverse momentum is considered, single-spin asymmetries can be generated either through quarks` angular motion or through transverely polarized quarks’ fragmentation processes. In the last decade, similar single-spin asymmetry phenomena have also been observed in semi-inclusive deep-inelastic scattering (e+N??e’+h+X), and very recently in inclusive hadron productions (e+N??h+X), on transversely polarized targets.I will describe recent experimental results and introduce upcoming transverse single-spin asymmetry measurements for polarized target Drell-Yan production at Fermilab (E1039, p+p? ?mu+mu- X), and for prompt photon and neutral pion productions in p?+p and p?+A collisions with the PHENIX experiment at RHIC

RHIC featured at NPR’s Science Friday: How to Make Quark Soup

October 20th, 2014 by geurts

Watch at this direct link to PRI’s video. Or, go to PRI’s Science Friday website at  How to Make Quark Soup and find audio and video links.

 

 

NPP Seminar by Mark Strikman (PSU)

October 15th, 2014 by geurts

Date: Tuesday  October 21, 2014 at noon
Location: 223 Herman Brown Hall, Rice University

Title: Transverse Geometry of the Hard and Soft pp and pA Collisions at the LHC
Speaker: Mark Strikman (PSU)

Abstract: Decades of studies of hard QCD phenomena provided a precision picture of the distribution of proton constituents (quarks and gluons) over the fraction of energy, x, which they carry in fast nucleons. More recently, studies of the hard exclusive processes provided first information about three dimensional structure of fast nucleons – the x-dependent impact parameter single parton distributions in the nucleon and led to the two scale geometric picture of the proton – proton interactions at the LHC. I will review how this picture explains a number of regularities of hadron production observed at the LHC, and reveals presence of the parton – parton correlations in nucleons. I will also present evidence for existence of significant fluctuations of gluon strength in nucleons as well as fluctuations of the overall strength of the interactions and discuss implications for pp and pA collisions.

RHIC featured on the Science Channel

August 15th, 2014 by geurts

The Relativistic Heavy-Ion Collider (RHIC) featured in “How The Universe Works” on the Science Channel. With STAR’s Mike Lisa (OSU) explaining RHIC’s role in exploring the building blocks of matter.

see BNL Newsroom feature

NPP Seminar by Kevin Dusling (PRL)

March 12th, 2014 by geurts

Date: Tuesday  March 18, 2014 at noon
Location: 223 Herman Brown Hall, Rice University

Title: Imaging the proton with multi-particle correlations at the LHC
Speaker: Kevin Dusling (PRL)
Abstract: The Large Hadron Collider at CERN is able to study the structure of the proton at shorter time scales and higher resolution then ever before. The first year of operation brought an entirely unexpected discovery; in proton-proton collisions a peculiar correlation between particles traveling in opposite directions was uncovered in extremely rare events. More recently, a similar correlation was observed in high multiplicity proton-lead collisions. We discuss the implications of these measurements on our understanding of the proton at high energies.

NPP Seminar by Paul Hohler (TAMU)

March 4th, 2014 by geurts

Date: Tuesday March 11, 2014  at 11am
Location: 223 Herman Brown Hall, Rice University

Title: Dileptons and chiral symmetry restoration
Speaker: Paul Hohler (TAMU)
Abstract: A long standing goal in heavy ion physics is to identify an experimental signal for chiral symmetry restoration. Ideally this can be achieved by comparing the in-medium spectral functions of chiral partners, such as the light vector and axial-vector mesons (rho and a1). While the in-medium rho spectral function can be obtained from interpretations of dilepton data in heavy ion collisions, measuring the in-medium a1 spectral function remains elusive. This talk will thus discuss theoretical techniques which can be used to calculate the in-medium axial-vector spectral function given a rho spectral function which describes available dilepton data so that the question of chiral symmetry can be critically addressed. We will demonstrate that the combination of QCD and Weinberg sum rules provide a powerful selection method for the axial-vector spectral functions. Using this at different temperatures, we can obtain a temperature progression from the vacuum towards restoration, and show that experimental results of the vector channel suggest compatibility with restoration.  Results will also be presented from an effective theory approach which can calculate the spectral functions in both channels in vacuum and in-medium from a microscopic perspective. This serves as a foundation for future systematic studies in this area.

NPP Seminar by Ivan Vitev (LANL)

January 31st, 2014 by geurts

Date: Tuesday  Febr. 18 2014, at noon
Location: 223 Herman Brown Hall, Rice University

Title: Jet physics with heavy ions at the LHC
Speaker: Ivan Vitev (LANL)
Abstract: In the past several decades, advances in the theory of strong interactions can be traced through theoretical and experimental developments in understanding the physics of jets in high-energy collider experiments. Jets have been instrumental in establishing Quantum Chromodynamics (QCD) and the parton model. Jet physics is the frontier where nuclear and particle physics intersect. In this talk, I will describe the theory that underlays jet production in ultra-relativistic collisions of heavy nuclei at the Large Hadron Collider (LHC).  I will show how insightful choices of experimental observables can help elucidate the differences between vacuum and in-medium parton showers and pinpoint the properties of the quark-gluon plasma (QGP) produced in heavy ion reactions. Toward the end of the talk I will discuss a new effective theory of jet propagation in matter that is being developed with the goal of improving heavy ion phenomenology.

NPP Seminar by Neha Shah (UCLA)

November 12th, 2013 by geurts

Date: Tuesday November 19, 2013 at noon
Location: 223 Herman Brown Hall, Rice University

Title: Search for exotics (H-dibaryon) with STAR
Speaker: Neha Shah (UCLA)
Abstract:

During past decade experiments at RHIC have shown that a strongly interacting, hot and dense partonic matter is formed in high energy nuclear collisions. The high temperature and presence of different flavor of quarks in the confined space makes heavy ion collisions the most suitable environment for the formation of multi-quark states like: tetra-quark, penta- quark and so on. The H-dibaryon is a multi-quark state with six quarks (uuddss) and was predicted by Jaffe in 1977. Considerable experimental efforts have been devoted to search for the H-dibaryon, however, there is no conclusive experimental evidence of its existence. At the STAR experiment we have tried two approaches to search for the H-dibaryon signal: measurement of Lambda-Lambda correlation function as well as reconstruction of signal using one of its weak decay mode H→Lambda-pi-p. In this talk, I will present the measurement of Lambda-Lambda correlations for sqrt(sNN) = 200 GeV in Au+Au collisions using the STAR experiment at RHIC. I will also discuss implications of measurements of Lambda-Lambda correlations on H-dibaryon search.

UH Physics Colloquium by Matt Luzum (LBNL)

October 25th, 2013 by geurts

On October 29 at 4pm   Matt Luzum (LBNL) will give a physics colloquium at UH.

UH Colloquia are scheduled on Tuesdays at 4:00pm in SR1 room 634.

 

NPP Seminar by Matt Luzum (LBNL)

October 24th, 2013 by geurts

Date: Wednesday Oct.30, 2013 at noon
Location: 223 Herman Brown Hall, Rice University

Title: Hot Quark Soup: Viscosity, Flow and Flow Fluctuations in Relativistic Heavy-Ion Collisions
Speaker: Matt Luzum (LBNL)
Abstract:
Relativistic heavy-ion collisions probe the properties of extremely
high temperature matter (~10^12 degrees), where there is expected to
exist a new phase of matter called the Quark-Gluon Plasma.  These
experiments indicate the presence of a medium that behaves as a
strongly-coupled, almost-perfect fluid.  I review some of the key
results that indicate this strong collective behavior, and outline the
current progress toward quantifying properties of the system, such as
the shear viscosity of the Quark-Gluon Plasma