Search for Low Scale Gravity Effects in e+e- Collisions at LEP

Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon is searched for as well as the effects of virtual graviton exchange in the processes: e+e- -> gamma gamma, ZZ, WW, mu mu, tau tau, qq and ee No evidence for this new interaction is found in the data sample collected by the L3 detector at LEP at centre-of-mass energies up to 183 GeV. Limits close to 1 TeV on the scale of this new scenario of quantum gravity are set

Production of Single W Bosons at LEP

We report on the observation of single W boson production in a data sample collected by the L3 detector at LEP2. The signal consists of large missing energy final states with a single energetic lepton or two hadronic jets. The cross-section is measured to be $0.61^{+0.43}_{-0.33} \pm 0.05 \; \rm{pb}$ at the centre of mass energy \sqrt{s}=172 \GeV{}, consistent with the Standard Model expectation. From this measurement the following limits on the anomalous $\gamma$WW gauge couplings are derived at 95\% CL: $\rm -3.6 \Delta \kappa_\gamma 1.5$ and $\rm -3.6 \lambda_\gamma 3.6$

Measurement of the Average Lifetime of b-Hadrons in Z Decays

We present a measurement of the average b-hadron lifetime ${\rm \tau_b}$ at the $\mathrm{e^+e^-} \,$ collider LEP. Using hadronic Z decays collected in the period from 1991 to 1994, two independent analyses have been performed. In the first one, the b-decay position is reconstructed as a secondary vertex of hadronic b-decay particles. The second analysis is an updated measurement of ${\rm \tau_b}$ using the impact parameter of leptons with high momentum and high transverse momentum. The combined result is \begin{center} ${\rm \tau_b= [ 1549 \pm 9 \, (stat) \, \pm 15 \, (syst) ] \; fs \,}$ . \end{center} In addition, we measure the average charged b-decay multiplicity ${\rm \langle n_{\rm b}} \rangle$ and the normalized average b-energy ${\rm \langle x_E \rangle_{\rm b}}$ at LEP to be \begin{center} ${\rm \langle n_{\rm b} \rangle = 4.90 \pm 0.04 \ (stat) \pm 0.11 \, (syst)}$ , \end{center} \begin{center} ${\rm \langle x_E \rangle_{\rm b} = 0.709 \pm 0.004 \, (stat + syst).}$ \end{center

Asymptomatic Post-Traumatic Rupture of the Right Diaphragm Dome

Aim.  This paper is aimed at presenting the materials of clinical observations associated with diagnosing rare-occurring ruptures of the right dome of the diaphragm that have been overlooked for a long period.Results.  A 61-year-old man was admitted to hospital with a diagnosis of chronic heart failure. Chest radiograph revealed a high position of the right dome of the diaphragm. Computed tomography revealed a defect in the central parts of the diaphragm on the right, the liver was rotated outward with its visceral surface deployed anteriorly and upward. In the right thoracic cavity, anterior to the liver, were the loops of the intestine and the outlet of the stomach.More than 30 years before, the patient had experienced an explosive trauma, which might have caused a rupture in the right dome of the diaphragm. A 70-year-old man, a smoker with a ten-year history of hypertension, was hospitalized with an increase in dyspnea, a cough with the discharge of purulent sputum, the feeling of heaviness behind the sternum. Chest radiograph revealed a high standing of the right dome of the diaphragm at the level of 3rd rib with a decrease in the volume of the right lung, and an increase in cardiac silhouette (cardiothoracic index 0.64). Computed tomography revealed a high standing of the right dome of the diaphragm as well as the compression of the middle and lower lobe of the right lung with the presence of compression atelectasis. The liver was rotated, displaced into the right thoracic cavity, the deformation of the inferior vena cava to the right was visualized due to the displacement and rotation of the liver. The consolidated fractures of 10th–12th ribs on the right were visualized. The patient had had a chest injury resulting from a traffic accident about 15 years before, with no X-ray examination having been conducted at that time.Conclusion.  In the case of left-sided diaphragm ruptures, which are much more frequent than the right-sided ones, the stomach, large and small intestines as well as spleen are displaced into the thoracic cavity. In the case of rightsided diaphragm ruptures, the liver and gallbladder are displaced into the thoracic cavity. Right-sided posttraumatic diaphragmatic hernias that are not diagnosed at the time of injury or trauma and continue to be asymptomatic for a number of years are very rare. The sensitivity and specificity of computed tomography for the diagnosis of diaphragm ruptures is 61–87 % and 72–100 %, respectively. In an acute period, the treatment of diaphragm ruptures is surgical. However, in long-term asymptomatic ruptures, expectant management is possible, particularly if the risk of surgical treatment is high

Asymptomatic Post-Traumatic Rupture of the Right Diaphragm Dome

Aim.  This paper is aimed at presenting the materials of clinical observations associated with diagnosing rare-occurring ruptures of the right dome of the diaphragm that have been overlooked for a long period.Results.  A 61-year-old man was admitted to hospital with a diagnosis of chronic heart failure. Chest radiograph revealed a high position of the right dome of the diaphragm. Computed tomography revealed a defect in the central parts of the diaphragm on the right, the liver was rotated outward with its visceral surface deployed anteriorly and upward. In the right thoracic cavity, anterior to the liver, were the loops of the intestine and the outlet of the stomach.More than 30 years before, the patient had experienced an explosive trauma, which might have caused a rupture in the right dome of the diaphragm. A 70-year-old man, a smoker with a ten-year history of hypertension, was hospitalized with an increase in dyspnea, a cough with the discharge of purulent sputum, the feeling of heaviness behind the sternum. Chest radiograph revealed a high standing of the right dome of the diaphragm at the level of 3rd rib with a decrease in the volume of the right lung, and an increase in cardiac silhouette (cardiothoracic index 0.64). Computed tomography revealed a high standing of the right dome of the diaphragm as well as the compression of the middle and lower lobe of the right lung with the presence of compression atelectasis. The liver was rotated, displaced into the right thoracic cavity, the deformation of the inferior vena cava to the right was visualized due to the displacement and rotation of the liver. The consolidated fractures of 10th–12th ribs on the right were visualized. The patient had had a chest injury resulting from a traffic accident about 15 years before, with no X-ray examination having been conducted at that time.Conclusion.  In the case of left-sided diaphragm ruptures, which are much more frequent than the right-sided ones, the stomach, large and small intestines as well as spleen are displaced into the thoracic cavity. In the case of rightsided diaphragm ruptures, the liver and gallbladder are displaced into the thoracic cavity. Right-sided posttraumatic diaphragmatic hernias that are not diagnosed at the time of injury or trauma and continue to be asymptomatic for a number of years are very rare. The sensitivity and specificity of computed tomography for the diagnosis of diaphragm ruptures is 61–87 % and 72–100 %, respectively. In an acute period, the treatment of diaphragm ruptures is surgical. However, in long-term asymptomatic ruptures, expectant management is possible, particularly if the risk of surgical treatment is high