arXiv subjects

V. Krutelyov

Publications and source records attributed to V. Krutelyov.

6 recordsLinked to original sources

arXiv2008

Searches for New Physics in Events with a photon and a missing energy at CDF Run II

The addition of the EMTiming system installed to provide the time measurements of the electromagnetic calorimeter signals has significantly increased the sensitivity of CDF to events with a photon and a missing energy. Here I review recent searches in this signature performed by CDF using data from proton-antiproton collisions at the center of mass energy of 1.96 TeV. They provide new constraints on models with large extra dimensions and with gauge mediated supersymmetry breaking.

hep-ex↗

arXiv2007

Rare decays of heavy flavor at the Tevatron

In this report I review recent results in the field of rare decays at the Tevatron CDF II and D0 experiments. The presentation is focused on rare decays of charm and bottom mesons with two muons in the final state. This includes improvements over the previously available limits on the following branching ratios: $B(D^+ \to π^+ μ^+ μ^-)< 4.7 \times 10^{-6}$, B(B_s^0 \to ϕμ^+ μ^-)< 3.2\times 10^{-6}$, $B(B_s^0 \to μ^+ μ^-)< 1 \times 10^{-7}$, and $B(B_d^0)< 3 \times 10{-8}$ all at the 90% confidence level. Also reported are the first direct observation of $D_s^+ \to ϕπ^+ \to μ^+ μ^- π^+$ with a significance above background of over 7 standard deviations and evidence of $D^+ \to ϕπ^+ \to μ^+ μ^- π^+$ with a significance of 3.1 and $B(D^+ \to ϕπ^+ \to μ^+ μ^- π^+)=(1.75 \pm0.7 \pm0.5) \times 10^{-6}$.

hep-ex↗

arXiv2005

The Timing System for the CDF Electromagnetic Calorimeters

We report on the design and performance of the electromagnetic calorimeter timing readout system (EMTiming) for the Collider Detector at Fermilab (CDF). The system will be used in searches for rare events with high energy photons to verify that the photon is in time with the event collision, to reject cosmic ray and beam halo backgrounds, and to allow direct searches for new heavy long-lived particles that decay to photons. The installation and commissioning of all 862 channels was completed in Fall 2004 as part of an upgrade to the Run II version of the detector. Using in-situ data, including electrons from W=>e nu and Z => ee decays, we measure the energy threshold for a time to be recorded to be 3.8 \pm 0.3GeV in the central portion of the detector and 1.9 \pm 0.1 GeV in the plug portion. Similarly, we measure a timing resolution of 600 \pm 10 ps and 610 \pm 10 ps for electrons above 10 GeV and 6 GeV respectively. There are very few system pathologies such as recording a time when no energy is deposited, or recording a second, fake time for a single energy deposit.

physics.ins-det↗

arXiv2005

A Combination of CDF and DO Limits on the Branching Ratio of B_s(d) to mu+ mu- Decays

We combine the results of CDF and DO searches for the rare decays B_s to mu+ mu- and B_d to mu+ mu-. The experiments use 364 pb-1 and 300 pb-1 of data respectively. The limits on the branching ratios are obtained by normalizing the estimated sensitivity to the decay B+ to J/psi K+, taking into account the fragmentation ratios f_u/f_s(d). The combined results exclude branching ratios of BR(B_s to mu+ mu-) > 1.5x10-7 and BR(B_d to mu+ mu- > 4.0x10-8 at 95% confidence level. These are the most stringent limits on these decays at the present time.

hep-ex↗

arXiv2004

B-physics: new states, rare decays and branching ratios in CDF

We present results and prospects for searches for rare B and D meson decays with final state dimuons, including B_s\toμμ, B_d\toμμ, and D\toμμ. Upper limits on the branching fractions are compared to previous CDF measurements, recent results from the B factories and theoretical expectations. We also report on new measurements of production and decay properties of the X(3872) particle, discovered in 2003 by the Belle Collaboration. New results on the measurement of the relative branching fraction for the Cabibbo suppressed decay B^+\to J/ψπ^+ Br(B^+\to J/ψπ^+)/Br(B^+\to J/ψK^+) are presented too. The presented results are based on the analyses of 70 to 220 pb^-1 of data collected by the CDF II detector in p\bar p collisions at \sqrt{s} = 1.96 GeV at Fermilab Tevatron.

hep-ex↗

arXiv2000

Prospect for Searches for Gluinos and Squarks at a Tevatron Tripler

We examine the discovery potential for SUSY new physics at a p{\bar p} collider upgrade of Tevatron with \sqrt s = 5.4 TeV and luminosity L ~= 4\times 10^{32} cm^{-2}s^{-1} (the Tripler). We consider the reach for gluinos and squarks using the experimental signatures with large missing transverse energy (\met) of jets + \met and 1l + jets + \met (where l=electron or muon) within the framework of minimal supergravity. The Tripler's strongest reach for the gluino is 1060 GeV for the jets + \met channel and 1140 GeV for the 1l + jets + \met channel for 30 fb^{-1} of integrated luminosity (approximately two years running time). This is to be compared with the Tevatron where the reach is 440(460) GeV in the jets + \met channel for 15(30) fb^{-1} of integrated luminosity.

hep-ph↗