Measurements of the production of forward jets from transversely polarized proton collisions at s=500 GeV conducted at the Relativistic Heavy Ion Collider (RHIC) are reported. Our measured jet cross ...section is consistent with hard scattering expectations. Our measured analyzing power for forward jet production is small and positive, and provides constraints on the Sivers functions that are related to partonic orbital angular momentum through theoretical models.
We report measurements of forward jets produced in Cu+Au collisions at \(\sqrt{s_{NN}}=200\) GeV at the Relativistic Heavy Ion Collider. The jet-energy distributions extend to energies much larger ...than expected by Feynman scaling. This constitutes the first clear evidence for Feynman-scaling violations in heavy-ion collisions. Such high-energy particle production has been in models via QCD string interactions, but so far is untested by experiment. One such model calls this a hadronic accelerator. Studies with a particular heavy-ion event generator (HIJING) show that photons and mesons exhibit such very high-energy production in a heavy-ion collision, so {\it QCD accelerator} appropriately captures the physics associated with such QCD string interactions. All models other than HIJING used for hadronic interactions in the study of extensive air showers from cosmic rays either do not include these QCD string interactions, or have smaller effects from the QCD accelerator.
We report measurements of forward jets and dijets produced in Cu+Au collisions at \(\sqrt{s_{NN}}=200\) GeV at the Relativistic Heavy Ion Collider. We also report dijet production cross sections in ...p+p collisions at \(\sqrt{s}=510\) GeV. We use the invariant dijet mass to search for indications of new particles. The p+p dijet results are compatible with string fragmentation models tuned to fit LHC data. The Cu+Au jet results far exceed Feynman scaling limits, and are compatible with models that incorporate string fusion to increase parton energy, acting as a QCD accelerator. The Cu+Au dijet results can be mostly explained by double parton scattering due to a parton flux from multiple p+p interactions with \(\sqrt{s}>>\sqrt{s_{NN}}\). Further indication of the increased parton energy is obtained from evidence of single- and double-\(\Upsilon\)(1S) production in the forward direction in Cu+Au collisions. Finally, we report evidence for the production of a new resonance, reconstructed from its dijet decay.
Measurements of the production of forward jets from transversely polarized
proton collisions at $\sqrt{s}=500$ GeV conducted at the Relativistic Heavy Ion
Collider (RHIC) are reported. Our measured ...jet cross section is consistent with
hard scattering expectations. Our measured analyzing power for forward jet
production is small and positive, and provides constraints on the Sivers
functions that are related to partonic orbital angular momentum through
theoretical models.
Measurements of the production of forward jets from transversely polarized proton collisions at \(\sqrt{s}=500\) GeV conducted at the Relativistic Heavy Ion Collider (RHIC) are reported. Our measured ...jet cross section is consistent with hard scattering expectations. Our measured analyzing power for forward jet production is small and positive, and provides constraints on the Sivers functions that are related to partonic orbital angular momentum through theoretical models.
Summary Objectives The purpose of the study was to determine if physical activity (PA) is a risk factor for persistent or recurrent hip pain in young and middle-aged persons with and without ...radiographic findings of cam or pincer morphology (CPM). Methods A population sample of persons aged 20–49 with (cases) and without (controls) hip pain in Metro Vancouver, Canada, was selected through random digit dialing (RDD). Self-reported PA was expressed as average energy expenditure (MET-hours) per year, over lifetime. CPM was defined as alpha angle >55°, lateral centre edge angle (LCE) >40°, or positive cross-over sign. Results Data were obtained for 500 subjects, 269 cases and 231 controls. Prevalence of radiographic CPM was 49% in the cases and 44% in the controls. In a logistic regression model adjusted for age, gender and CPM, total lifetime PA, including occupational, domestic and recreational activities, was significantly associated with hip pain (Odds ratio (OR) 1.30 per 1000 MET-hours, 95% CI 1.15–1.38). The effect of total PA was observed in those with CPM (1.44, 1.17–1.78) and without CPM (1.23, 1.04–1.45). For domestic activities, the association was seen only in those with CPM (significant interaction). When PA was categorized into quartiles, higher levels of PA were associated with a greater risk of pain. Conclusions PA, as measured by average energy expenditure over lifetime is a risk factor for hip pain in young and middle-aged persons. For some activities, the risk is likely increased in persons with radiographic evidence of CPM.
PDF
