arXiv subjects

A. Aurisano

Publications and source records attributed to A. Aurisano.

185 records · Page 11Linked to original sources

arXiv2011

Measurement of branching ratio and Bs0 lifetime in the decay Bs0 -> J/psi f0(980) at CDF

We present a study of Bs0 decays to the CP-odd final state J/psi f0(980) with J/psi -> mu+ mu- and f0(980) -> pi+ pi-. Using ppbar collision data with an integrated luminosity of 3.8/fb collected by the CDF II detector at the Tevatron we measure a Bs0 lifetime of tau(Bs0 -> J/psi f0(980)) = 1.70 -0.11+0.12(stat) +-0.03(syst) ps. This is the first measurement of the Bs0 lifetime in a decay to a CP eigenstate and corresponds in the standard model to the lifetime of the heavy Bs0 eigenstate. We also measure the product of branching fractions of Bs0 -> J/psi f0(980) and f0(980) -> pi+ pi- relative to the product of branching fractions of Bs0 -> J/psi phi and phi -> K+ K- to be R_f0/phi = 0.257 +_0.020(stat) +-0.014(syst), which is the most precise determination of this quantity to date.

hep-ex↗

arXiv2011

Search for New Dielectron Resonances and Randall-Sundrum Gravitons at the Collider Detector at Fermilab

A search for new dielectron mass resonances using data recorded by the CDF II detector and corresponding to an integrated luminosity of 5.7/fb is presented. No significant excess over the expected standard model prediction is observed. In this dataset, an event with the highest dielectron mass ever observed (960 GeV/c^2) was recorded. The results are interpreted in the Randall-Sundrum (RS) model. Combined with the 5.4/fb diphoton analysis, the RS-graviton lower mass limit for the coupling k/\bar{M}_{Pl}=0.1 is 1058 GeV/c^2, making it the strongest limit to date.

hep-ex↗

arXiv2010

Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |η| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of η-ϕspace; toward, away, and transverse, where ϕis the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte-Carlo models. The goal of this analysis is to provide data that can be used to test and improve the QCD Monte-Carlo models of the underlying event that are used to simulate hadron-hadron collisions.

hep-ex↗

arXiv2006

Detection of SUSY Signals in Stau Neutralino Co-annihilation Region at the LHC

We study the prospects of detecting the signal in the stau neutralino co-annihilation region at the LHC using tau leptons. The co-annihilation signal is characterized by the stau and neutralino mass difference (dM) to be 5-15 GeV to be consistent with the WMAP measurement of the cold dark matter relic density as well as all other experimental bounds within the minimal supergravity model. Focusing on tau's from neutralino_2 --> tau stau --> tau tau neutralino_1 decays in gluino and squark production, we consider inclusive MET+jet+3tau production, with two tau's above a high E_T threshold and a third tau above a lower threshold. Two observables, the number of opposite-signed tau pairs minus the number of like-signed tau pairs and the peak position of the di-tau invariant mass distribution, allow for the simultaneous determination of dM and M_gluino. For dM = 9 GeV and M_gluino = 850 GeV with 30 fb^-1 of data, we can measure dM to 15% and M_gluino to 6%.

hep-ph↗

arXiv2006

Measurement of the Stau Minus Neutralino Mass Difference and Mgluino in the Co-Annihilation Region at the LHC

We study the prospects for the measurement of the stau - lightest neutralino mass difference (dM) and the gluino mass (Mg) in the supersymmetric co-annihilation region at the LHC using tau leptons. Recent WMAP measurements of the amount of cold dark matter and previous accelerator experiments indicate that the coannihilation region of mSUGRA is characterized by a small dM (5-15 GeV). Focusing on taus from N2 -> tau stau -> tau tau N1 decays in gluino and squark production, we consider inclusive 3 tau+jet+missing Et production, with two taus above a high Et threshold and a third tau above a lower threshold. Two observables, the number of opposite-signed tau pairs minus the number of like-signed tau pairs and the peak of the ditau invariant mass distribution, allow for the simultaneous determination of dM and Mg for dM >5 GeV. For example, for dM = 9 GeV and Mg =850 GeV and with 30 fb^-1 of data, we can measure dM to 15% and Mg to 6%.

hep-ph↗