Update hard_scatter/ttbar/v1 dataset card

README.md

@@ -297,6 +297,79 @@ This dataset is designed for machine learning tasks in high-energy physics, incl
 
 N/A (Physics data)
 
+## Quick Start
+
+### Installation
+
+```bash
+pip install datasets pyarrow
+```
+
+### Load First 100 Events (All Objects)
+
+```python
+from datasets import load_dataset
+
+# Load first 100 rows of each configuration
+particles = load_dataset("OpenDataDetector/ColliderML_ttbar_pu0", "particles", split="train[:100]")
+tracker_hits = load_dataset("OpenDataDetector/ColliderML_ttbar_pu0", "tracker_hits", split="train[:100]")
+calo_hits = load_dataset("OpenDataDetector/ColliderML_ttbar_pu0", "calo_hits", split="train[:100]")
+tracks = load_dataset("OpenDataDetector/ColliderML_ttbar_pu0", "tracks", split="train[:100]")
+
+print(f"Loaded {len(particles)} particle events")
+print(f"Loaded {len(tracker_hits)} tracker hit events")
+print(f"Loaded {len(calo_hits)} calo hit events")
+print(f"Loaded {len(tracks)} track events")
+```
+
+### Load Specific Columns from First 100 Events
+
+```python
+from datasets import load_dataset
+import numpy as np
+
+# Load only specific columns from particles
+particles = load_dataset(
+    "OpenDataDetector/ColliderML_ttbar_pu0",
+    "particles",
+    split="train[:100]",
+    columns=["event_id", "px", "py", "pz", "energy", "pdg_id"]
+)
+
+# Access data
+for event in particles:
+    event_id = event['event_id']
+
+    # Convert to numpy arrays
+    px = np.array(event['px'])
+    py = np.array(event['py'])
+    pz = np.array(event['pz'])
+
+    # Calculate transverse momentum
+    pt = np.sqrt(px**2 + py**2)
+
+    print(f"Event {event_id}: {len(px)} particles, mean pt = {pt.mean():.2f} GeV")
+
+# Load only specific columns from tracks
+tracks = load_dataset(
+    "OpenDataDetector/ColliderML_ttbar_pu0",
+    "tracks",
+    split="train[:100]",
+    columns=["event_id", "qop", "theta", "phi"]
+)
+
+# Calculate derived quantities
+for event in tracks:
+    qop = np.array(event['qop'])
+    theta = np.array(event['theta'])
+
+    # Compute transverse momentum from track parameters
+    pt = np.abs(1.0 / qop) * np.sin(theta)
+    eta = -np.log(np.tan(theta / 2.0))
+
+    print(f"Event {event['event_id']}: {len(qop)} tracks, pt range [{pt.min():.2f}, {pt.max():.2f}] GeV")
+```
+
 ## Dataset Structure
 
 ### Data Instances